- Hypercoordinate aryltrialkylsilanes and -stannanes and their use in the synthesis of homodinuclear organometallic complexes with a 1,4-phenylene bridge
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New mono- and dinuclear aryltrialkylsilanes and -stannanes [Me3M{C6H3(CH2NMe2) 2-2,6}] (M = Si (5), Sn (6)) and [(Me3M)2-1,4-{C6(CH2NMe 2)4-2,3,5,6}] (M = Si (9), Sn (10)) have been prepared from transmetalation reactions of dimeric [Li{C6H3(CH2NMe2)2-2,6}]2 and new polymeric [Li2-1,4-{C6(CH2NMe2) 4-2,3,5,6}]∞ with (trimethylsilyl)trifluoromethanesulfonate or trimethyltin chloride. The X-ray crystal structures of dinuclear 9 and 10 have been determined and in the molecular geometries found the central 1,4-phenylene dimetalated aryl ligand system provides bidentate C,N-coordination to silicon in 9 and terdentate pseudofacial N,C,N′-coordination to tin in 10. Reactions of the newly prepared silanes 5 and 9 and stannanes 6 and 10 with diverse palladium(II) and platinum(II) substrates afford organometallic products arising from both aryl and methyl group transfer. For example, the reaction of dinuclear stannane 10 (or dinuclear silane 9) with palladium(II) species gives the bimetallic complex [(PdCl)2-1,4-{C6(CH2NMe2) 4-2,3,5,6}] (15), whereas its reaction with [PtCl2(COD)] (COD = cycloocta-1,5-diene) or Me3SnCl gives the ionic tin(IV) species [(Me2-Sn)2-1,4-{C6(CH2NMe 2)4-2,3,5,6}]2+(X-)2 with X being Cl (18a) or Me3SnCl2 (18b). The X-ray crystal structure of 18b has been determined and the molecular geometry found shows that the central dimetalated aryl ligand system provides terdentate meridional N,C,N′-coordination to both tin centers.
- Steenwinkel, Pablo,Jastrzebski, Johann T. B. H.,Deelman, Berth-Jan,Grove, David M.,Kooijman, Huub,Veldman, Nora,Smeets, Wilberth J. J.,Spek, Anthony L.,Van Koten, Gerard
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- Polysulfonylamine XXXV. Synthese, Roentgenstrukturanalysen und hochaufgeloeste Festkoerper-NMR-Spektren der ionischen Organozinn(IV)-dimesylamide und 2
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(4) was prepared by treating Me3SnN(SO2Me)2 (1) with liquid ammonia; single crystals suitable for X-ray diffraction were grown from a solution in liquid ammonia by slow evaporation of the solvent at -42 deg C. 2 (5) was obtained from dimethyl sulfoxide and Me2Sn2 or 1 in refluxing CCl4, the co-product in the latter case being SnMe4.The crystallographic data at -95 deg C are for 4: monoclinic, space group P21/c, a 650.3(2), b 1464.7(3), c 1479.6(4) pm, β 94.63(2) deg, U 1.4046 nm3, Z=4; for 5: triclinic, space group P, a 818.3(2), b 986.6(2), c 1119.9(3) pm, α 79.10(2), β 77.51(2), γ 77.58(2) deg, U 0.8524 nm3, Z=1.The structure refinement of 4 was based on 3092 reflections with F>4?(F) to give R=0.018.For 5, refinement using 3579 reflections with F>4?(F) yielded R=0.021.The crystals of both compounds consist of discrete (MeSO2)2N- anions and Me3Sn(NH3)2+ or Me2Sn(DMSO)42+ cations, respectively.The structures of the anions are similar to those observed in other ionic dimesylamides.In the cation of 4, the tin atom has an axially distorted trigonal-bipyramidal environment with apical NH3 molecules (Sn-N 232.8 and 238.3, Sn-C 211.7-212.4 pm, N-Sn-N 179.2, C-Sn-C 118.1-122.1, N-Sn-C 88.0-91.3 deg).The tin atom in the centrosymmetric cation of 5 displays trans-octahedral geometry with four DMSO molecules bonded through their oxygen atoms (Sn-C 211.4, Sn-O 219.9 and 221.4 pm, (O-Sn-O)cis 88.9 and 91.1, O-Sn-C 86.8-93.2 deg).The oxygen centres of the sulfoxide ligands are sp2-hybridized with Sn-O-S 121.8 and 123.1 deg, S-O 154.4 and 155.4 pm. 5 is the first example of a structurally characterized tin(IV)-sulfoxide complex in which four sulfoxide ligands are coordinated to a single tin centre. 13C, 15N and 119Sn CP/MAS NMR spectra of solid 4 and 5 agree very well with the X-ray diffraction results.In both cases, the isotropic 119Sn chemical shifts and their tensorial properties support the nearest-neighbours-environment as shown by crystallography.The slight inequivalences of the NH3 and DMSO ligands, respectively, are mirrored in the 15N and 13C CP/MASS spectra of 4 and 5.The 119Sn CP/MAS spectrum of 4 is complicated by the simultaneous presence of scalar and quadrupolar coupling of two inequivalent 14N nuclei with 119Sn.
- Blaschette, Armand,Hippel, Ilona,Krahl, Juergen,Wieland, Elke,Jones, Peter G.,Sebald, Angelika
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- Vibrational Spectra and Normal Coordinate Calculations for Trimethylstannane
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The infrared and Raman spectra of trimethylstannane and its deuterated analogues were obtained.Assignments for all the fundamentals except internal torsions were made and normal coordinate calculations were carried out to confirm the proposed assignments.
- Imai, Yoshika,Aida, Koyo
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- Ultrasonic Effects on Electroorganic Processes. Part 9. Current Efficiency and Product Selectivity in the Electroreduction of Alkyl Halides to Alkyl Stannanes at a Reactive Tin Cathode
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The ultrasonic effects on the electroreduction of methyl and allyl halides (RX) to the corresponding stannanes (R3SnSnR3 and R4Sn) at a reactive (consumable) tin cathode were examined. The current efficiency and product selectivity for the reduction were found to be greatly affected by ultrasonic irradiation. For instance, the selectivity for (CH3)3SnSn(CH3)3 to (CH3)4Sn from CH3I was significantly increased under irradiation. This fact is rationalized as being due to because the intermediate species [(CH3)3Sn·] formed by the primary one-electron reduction of CH3I are activated for their coupling by mobilization on/from the cathode surface under irradiation. On the other hand, the ultrasonic effects on the reduction of CH3Br and C3H5Br seemed to be slightly different from those in the reduction of CH3I.
- Atobe, Mahito,Nonaka, Tsutomu
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- The first 1,1′-Digallylferrocene and a rodlike, polymeric donor-acceptor complex: Synthesis, properties, and structure of [Fe(η5-C5H4GaMe2)2] n and [Fe(η5-C5H4GaMe2)2(C 12H8N2)]n
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The reaction of 1,1?-bis(trichlorostannyl)ferrocene with trimethylgallium results in the formation of Fe(C5H4GaMe2)2 (1), the first digallylferrocene. An X-ray crystal structure analysis of 1 reveals a polymeric structure. NMR data confirm a monomeric structure of [1-2 donor] in donor solvents. The reaction of 1 with phenazine results in the formation of the supramolecular polyferrocene [1·phenazine]n. Its rodlike structure is proven by X-ray crystallography.
- Althoff, Alexander,Jutzi, Peter,Lenze, Norman,Neumann, Beate,Stammler, Anja,Stammler, Hans-Georg
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- Group 13 and 14 alkyl derivatives of the imido-nitrido metalloligand [{Ti(η5-C5Me5)(μ-NH)} 3(μ3-N)]
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The reactivity of the imido-nitrido trinuclear complex [{Ti- (η5-C5Me5)(μ-NH)}3(μ 3-N)] (1) toward alkyl derivatives of group 13 and 14 elements has been investigated. Treatment of 1 with trialkyl der
- Garcia-Castro, Maria,Martin, Avelino,Mena, Miguel,Yelamos, Carlos
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- SYNTHESE VON SULFINSAEUREIMIDAMIDOSTANNANEN
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N-Lithiomethanesulfinicacidimide amides of the general composition MeS(NR)NRLi (II) are prepared by addition of methyllithium to sulfur diimides RN=S=NR (I) (R=t-Bu or SiMe3).The corresponding reaction with Me3Sn-N=S=N-SnMe3 yields the N-lithio salt (Me3S
- Haenssgen, Dieter,Steffens, Reinhard
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- Cleavage reactions of group IVa metal-metal bonds
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The reactions of hexamethyldimetal compounds containing unsymmetrical metal-metal bonds with iodine monochloride, hydrogen chloride, and trifluoroiodomethane are reported. The hypothesis that products of similar reactions are determined by polarity of the
- Shaw III, C. Frank,Allred
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- The reactivity of metal-metal bonds. II. The tin-manganese bond
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The reactions of trimethyltinpentacarbonylmanganese with tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, and ethylene are described. Only with tetrafluoroethylene is an adduct, namely, (CH3)3SnCF2CF2Mn(CO)5, obtained, although trimethyltin fluoride and fluorocarbon-carbonylmanganese products are also formed. With trifluoroethylene and chlorotrifluoroethylene, trimethyltin halides and fluorovinylpentacarbonylmanganese compounds are produced, although in the latter case perfluoroacryloylpentacarbonylmanganese, CF2=CFCOMn(CO)5, is a major product. Ethylene does not cleave the Sn-Mn bond, but rather displaces carbon monoxide to form (CH3)3SnMn(CO)4(π-C2H 4). The spectroscopic properties of the new compounds are discussed.
- Clark,Tsai
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- Octahedral Bis(phenoxy-imine)tin(IV) alkyl complexes: Synthesis, characterization, and reactivity toward ionizing species and ethylene
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The synthesis of new organotin compounds of the general formula L 2SnR2 (L = N-(3-tert-butylsalicylidene)-2,3,4,5,6- pentafluoroaniline; R = CH3 (1), n-C4H9 (3)) and L′2SnR2 (L′ = Ar-(3-tert- butylsalicylidene)aniline; R = CH3 (2), n-C4H9 (4)) is described herein. The compounds were characterized by 1H, 13C, and 119Sn NMR in solution; in some cases a fluxional behavior was observed by variable-temperature experiments. Characterization by single-crystal X-ray diffraction analysis has been obtained for compounds 1, 2, and 4. The reactivity of the synthesized compounds toward ionizing agents was studied by an NMR-tube reaction. Compounds 2 and 4 underwent an alkyl abstraction reaction with the carbenium salt [C(C6H5) 3]+[B(C6F5)4] . The obtained cationic species exhibited some activity in the oligomerization of ethylene under mild conditions, producing short-chain oligomers, with saturated end groups and methyl branches.
- Annunziata, Liana,Pappalardo, Daniela,Tedesco, Consiglia,Pellecchia, Claudio
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- ORGANOMETALLIC COMPOUNDS AND METHODS FOR THE DEPOSITION OF HIGH PURITY TIN OXIDE
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Disclosed herein are compounds useful for the deposition of high purity tin oxide. Also disclose are methods for the deposition of tin oxide films using such compounds. Such films demonstrate high conformality, high etch selectivity and are optically transparent. Such compounds are those of the Formula as follows R x -Sn-A 4-x wherein: A is selected from the group consisting of (Y a R' z ) and a 3- to 7-membered N- containing heterocyclic group; each R group is independently selected from the group consisting of an alkyl or aryl group having from 1 to 10 carbon atoms; each R' group is independently selected from the group consisting of an alkyl, acyl or aryl group having from 1 to 10 carbon atoms; x is an integer from 0 to 4; a is an integer from 0 to 1; Y is selected from the group consisting of N, O, S, and P; and z is 1 when Y is O, S or when Y is absent and z is 2 when Y is N or P.
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Paragraph 0103
(2019/02/17)
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- Preparation of NHC Stabilized Al(III)fluorides: Fluorination of [(SIMes)AlMe3] with SF4 or Me3SnF
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Various reaction routes have been developed to synthesize the N-heterocyclic carbene (NHC) stabilized Al(III) fluorides [(SIMes)Al(F)3] (2) and [(SIMes)Al(F)Me2] (3) through fluorination of [(SIMes)AlMe3] (1) (SIMes: 1,3-bis(2,4,6-trimethylphenyl)-imidazolidin-2-ylidene) with fluorinating agents such as SF4, SF6 and Me3SnF. The reactivity of 2 was investigated towards a F/Cl exchange reaction by treating it with Me3SiCl.
- Tomar, Pooja,Braun, Thomas,Kemnitz, Erhard
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p. 4735 - 4739
(2019/11/19)
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- A utility for organoleads: Selective alkyl and aryl group transfer to tin
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Me4Pb and Ph4Pb readily transfer methyl or phenyl groups to an equivalent molar ratio of tin(iv) chlorides in the order SnCl4 > MeSnCl3 > Me2SnCl2 > Me3SnCl, often in a selective manner. Me3PbCl and Ph3PbCl specifically transfer a single methyl/phenyl group under the same reaction conditions to produce recovered yields in >75%. Specific transfer of 2 methyl groups from PbMe4 can be achieved at elevated temperatures and/or a 2:1 molar ratio Pb:Sn.
- Arias-Ugarte, Renzo N.,Pannell, Keith H.
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p. 1703 - 1708
(2018/02/09)
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- Formation of silicon-carbon bonds by photochemical irradiation of (η5-C5H5)Fe(CO)2SiR3 and (η5-C5H5)Fe(CO)2Me to Obtain R3SiMe
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Photochemical irradiation of an equimolar mixture of (η5 -C5H5)Fe(CO)2SiR3, FpSiR 3, and FpMe leads to the efficient formation of the silicon-carbon-coupled product R3SiMe, R3 = Me 3, Me2Ph, MePh2, Ph3, ClMe 2, Cl2Me, Cl3, Me2Ar (Ar = C 6H4-p-X, X = F, OMe, CF3, NMe2). Similar chemistry occurs with related germyl and stannyl complexes at slower rates, Si > Ge Sn. Substitution of an aryl hydrogen to form FpSiMe2C6H4-p-X has little effect on the rate of the reaction, whereas progressive substitution of methyl groups on silicon by Cl slows the process. Also, changing FpMe to FpCH2SiMe3 dramatically slows the reaction as does the use of (η5-C 5Me5)Fe(CO)2 derivatives. A mechanism involving the initial formation of the 16e intermediate (η5-C 5H5)Fe(CO)Me followed by oxidative addition of the Fe-Si bond accounts for the experimental results obtained.
- Fortier, Skye,Zhang, Yongqiang,Sharma, Hemant K.,Pannell, Keith H.
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p. 1041 - 1044
(2010/04/25)
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- Synthesis, molecular structure and reactivity of the dimethyl sulfide adduct of a 1,3,2-diselenaborolane with an annelated dicarba-closo- dodecaborane(12) unit
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The reaction of 1,2-diselenolato-1,2-dicarba-closo-dodecaborane(12) dianion [1,2-(1,2-C2B10H10)Se2] 2- with HBBr2-SMe2 affords the dimethylsulfide adduct of 4,5-[1,2-dicarba-closo-dodecaborano(12)]-1,3-diselena -2-borolane in good yield. The molecular structure was determined by X-ray diffraction, and the solution-state structure was established by NMR spectroscopy (1H, 11B, 13C, 77Se NMR). 11B and 77Se chemical shifts were reproduced by DFT calculations. Attempts were made to abstract dimethyl sulfide, and the parent donor-free compound could be detected in solution. The reactivity of the title compound was studied towards pyridine, Me3SnF,[Pt(PPh3)2(C2H 4)], tert-Bu -OH, AlMe3 and AlH3-N(Et)Me 2 as well as a hydroborating reagent.
- Wrackmeyer, Bernd,Klimkina, Elena V.,Milius, Wolfgang
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p. 2324 - 2334
(2010/09/06)
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- Preparation and structural characterization of trimethyltin(iv) tropolonate. Investigation of a rare methyl-migrational dismutation in the solution, solid and liquid states
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The synthesis and structural characterisation, by low temperature X-ray diffraction and solid-state NMR, of the highly reactive monomeric Me 3Sn(trop) (1) complex has been studied; 1 rearranges into Me 2Sn(trop)2 (2) and Me4Sn by methyl-transfer dismutation. Based on the NMR kinetic data it appears that complex 1 demethylates faster in the solid and liquid than in dilute CDCl3 solution, but with a slower rate than in dilute CD3OD solution. The Royal Society of Chemistry 2007.
- Deak, Andrea,Kiraly, Peter,Tarkanyi, Gabor
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p. 234 - 239
(2007/10/03)
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- Reactions of the titanium-carbide species CpTi(μ2-Me)(μ2-NPi-Pr3)(μ4-C)(AlMe2)3
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The reaction of CpTi(μ2-Me)(μ2-NPi-Pr3)(μ4-C)(AlMe2)3 with ClSnMe3 and MeO3SCF3 affords the species CpTi(μ2-Cl)(μ2-NPi-Pr3)
- Graham, Todd W.,Ong, Christopher,Wei, Pingrong,Stephan, Douglas W.
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p. 4481 - 4485
(2008/02/13)
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- Triorganotin(IV) derivatives of umbelliferone (7-hydroxycoumarin) and their adducts with 1,10-phenanthroline: Synthesis, structural and biological studies
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New triorganotin(IV) derivatives of the general formula R 3Sn(Umb) (where, R = Me, n-Bu and Ph; Umb = umbelliferone anion) have been synthesized using sodium salt method. Further, the adducts of the general formula R3Sn(Umb)·phen (where R = Me and Ph; phen = 1,10-phenanthroline) have also been synthesized by the interaction of the triorganotin(IV) derivatives of umbelliferone with 1,10-phenanthroline. The bonding and coordination behavior of these derivatives are discussed on the basis of IR, NMR (1H, 13C and 119Sn), and 119Sn Mo?ssbauer spectroscopic studies. These investigations indicate that umbelliferone acts as a monoanionic bidentate ligand in R 3Sn(Umb) coordinating through O(7) and O(1) in the solid-state. These polymeric R3Sn(Umb) derivatives (where R = Me and n-Bu) have been proposed to have a trans-trigonal bipyramidal geometry with the three R groups in equatorial positions, while the axial positions are occupied by a phenolic oxygen and the O(1) atom from the adjacent molecule. A pseudotetrahedral geometry has been suggested for Ph3Sn(Umb). A distorted octahedral geometry around tin has been proposed for R3Sn(Umb)·phen, in which umbelliferone anion acts as a monodentate ligand coordinating through phenolic oxygen O(7). The newly synthesized derivatives have been assayed for their anti-inflammatory, cardiovascular and anti-microbial activities. The average LD50 values >1000 mg kg-1 of these derivatives indicate their safety margin. Among all the compounds tested, Ph 3Sn(Umb)·phen has been found to show potent anti-inflammatory activity with low mammalian toxicity and mild hypotensive activity.
- Nath, Mala,Jairath, Ruchi,Eng, George,Song, Xueqing,Kumar, Ashok
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p. 134 - 144
(2007/10/03)
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- Solution NMR study of methyltin(IV)-cupferronates: Analysis of a unique dismutation reaction and preorganization process
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The solution nuclear magnetic resonence of methyltin(IV)-cuferronates and a unique dismutation reaction and preorganization process was analyzed. The mechanism of the methyl-migrational process was proposed on the basis of solvent induced conformational equilibrium. Kinetic experiments in the NMR was carried out to prove the deduction concerning the reaction mechanism. It was observed that stronger lewis base solvents induced dismutation at markedly faster rates than methanol.
- Tarkanyi, Gabor,Deak, Andrea
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p. 3784 - 3791
(2008/10/09)
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- Cine-Substitution in the Stille Coupling: Evidence for the Carbenoid Reactivity of sp3-gem-Organodimetallic Iodopalladio-trialkylstannylalkane Intermediates
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Two complementary routes to sp3-gem-organodimetallic iodopalladio-trialkylstannanylalkanes are presented. Such intermediates have been proposed as Pd-carbenoid precursors in the Busacca-Farina cine-substitution mechanism in the Stille coupling. The decomposition of iodomethyltrialkylstannanes by Pd(0) catalysts was monitored by 1H, 2D, and 119Sn NMR. The formation of ethylene, trace formaldehyde, and iodotrialkylstannanes was detected. When the reaction was carried out in the presence of norbornene, the corresponding cyclopropane was produced in good yield. These observations are consistent with the intermediacy of a Pd-carbenoid species. sp3-gem-Organodimetallic iodopalladio-trialkylstannanylalkane complexes were also prepared under stoichiometric conditions via transmetalation from tin to Pd(II). Me3SnCH2Sn(CH2CH2CH2)3 reacted with [(D-t-BPF)PdI]+I-, yielding the (D-t-BPF)Pd(II)ICH2SnMe3 complex that dimerized to form ethylene and cyclopropanated norbornene. The carbenoid reactivity of iodopalladio-trialkylstannanylalkanes complexes validates the Busacca-Farina mechanism of the cine-substitution in the Stille coupling. Copyright
- Fillion, Eric,Taylor, Nicholas J.
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p. 12700 - 12701
(2007/10/03)
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- First gas-phase detection of dimethylstannylene and time-resolved study of some of its reactions
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Using a laser flash photolysis/laser probe technique, we report the observation of strong absorption signals in the wavelength region 450-520 nm (highest intensity at 514.5 nm) from four potential precursors of dimethylstannylene, SnMe2, subjected to 193 nm UV pulses. From GC analyses of the gaseous products, combined with quantum chemical excited state CIS and TD calculations, we can attribute these absorptions largely to SnMe2, with SnMe4 as the cleanest source of the species. Kinetic studies have been carried out by time-resolved monitoring of SnMe2. Rate constants have been measured for its reactions with 1,3-C4H6, MeC, CMe, MeOH, 1-C4H9Br, HCl, and SO2. No evidence could be found for reaction of SnMe2 with C2H4, C3H8, Me3SiH, GeH4, Me2GeH2, or N2O. Limits of less than 10-13 cm3 molecule-1 s-1 were set for the rate constants for these latter reactions. These measurements showed that SnMe2 does not insert readily into C-H, Si-H, Ge-H, C-C, Si-C, or Ge-C bonds. It is also unreactive with alkenes although not with dienes or alkynes. It is selectively reactive with lone pair donor molecules. The possible mechanisms of these reactions are discussed. These results represent the first visible absorption spectrum and rate constants for any organo-stannylene in the gas phase.
- Becerra, Rosa,Boganov, Sergey E.,Egorov, Mikhail P.,Faustov, Valery I.,Krylova, Irina V.,Nefedov, Oleg M.,Walsh, Robin
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p. 7555 - 7562
(2007/10/03)
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- Carbanions as intermediates in the formation of Grignard reagents
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The formation of reactive carbanions in Grignard reagents was discussed. Inter- and/or intramolecular migrations of organotin and organosilicon groups were also studied. Results showed that the high percentage of rearrangement reactions proves that the anionic species are not located on a minor pathway.
- Van Klink, Gerard P.M.,De Boer, Henricus J.R.,Schat, Gerrit,Akkerman, Otto S.,Bickelhaupt, Friedrich,Spek, Anthony L.
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p. 2119 - 2135
(2008/10/08)
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- Alkyl-substituted allylic lithium compounds: Structure and dynamic behavior
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Several methyl-substituted allylic lithium compounds have been prepared by CH3Li cleavage of their corresponding bis(methyl)bis(allylic)stannanes. Low-temperature 13C and proton NMR studies of 1:1 complexes of these allylic lithium compounds with TMEDA establish their structures. NMR line shape changes with temperature provide barriers to rotation. Results are listed in order as follows (allyl substituents, compound number, barrier to rotation in kcal·mol-1, and bonds undergoing rotation): 1,1-dimethyl, 26, 18, 2-3; endo-1-methyl, 27, 19, 2-3; endo-1-exo-3-dimethyl, 28, 21, 1-2 and 2-3. These observations together with the allylic 13C NMR chemical shifts indicate that in the case of unsymmetrical alkyl substitution at the termini the allyl C-C bond to the more substituted terminus is of higher bond order than that to the less substituted terminus. Unsymmetrical substitution is proposed to reduce the degree of delocalization compared to the symmetrically substituted allylic lithium compounds. A mechanism is proposed for the rotation process which is consistent with the Eyring activation parameters.
- Fraenkel,Qiu
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p. 12806 - 12812
(2007/10/03)
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- Carbamoylstannation of terminal alkynes with carbamoylstannanes: catalyst-dependent regiochemical reversal
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Rh(acac)(CO)2 catalyzes addition of (N,N-diisopropylcarbamoyl)trimethylstannane to terminal alkynes to give (Z)-β-stannyl-α,β-unsaturated amides with terminal attachment of the amide group, while the use of Ni(cod)2 results in the reversal of the regioselectivity. A mechanism initiated by the oxidative addition of the carbamoylstannane was proposed on the basis of the isolation of (trimethylstannyl)(N,N-diisopropylcarbamoyl)[1, 2-bis(dimethylphosphino)ethane]palladium.
- Hua, Ruimao,Onozawa, Shun-Ya,Tanaka, Masato
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p. 3269 - 3271
(2008/10/08)
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- Synthesis of 1,3,5-tri- and 1,2,4,5-tetrasubstituted tin and mercury derivatives of benzene. Crystal structure of 1,3,5-tris(chloromercurio)benzene
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The reaction of 1,3,5-tribromo- or 1,2,4,5-tetrabromobenzene with trimethylstannyl sodium in tetraglyme gave the corresponding polystannylated benzene derivatives 2 and 4, respectively, in high yield. They were converted with mercuric chloride to the corresponding tris- and tetrakis(chloromercurio)benzenes 5 and 6, respectively. The structure of 5 was confirmed by X-ray crystallography. Some spectral properties of the new compounds are discussed. The (partial) conversion of 2 to 1,3,5-trilithiobenzene (8) was also investigated.
- Rot, Nicolette,De Kanter, Frans J.J.,Bickelhaupt, Friedrich,Smeets, Wilberth J.J.,Spek, Anthony L.
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p. 369 - 379
(2007/10/03)
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- Decomposition of ethoxyethynyl(trimethyl)tin - Studied by 119Sn and 13C NMR spectroscopy
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The thermally induced decomposition of ethoxyethynyl(trimethyl)tin (1) was studied by 119Sn NMR which revealed the formation of bis(trimethylstannyl) ketene (2) as the major product, bis(trimethylstannyl) acetic acid ethyl ester (3) as a minor product, and a small amount of tetramethyltin (4). Full NMR data sets, including coupling constants and isotope induced chemical shifts 1 Δ12/13C(119Sn) are provided for 1-3. The first example of ultra-high resolution 119Sn NMR is shown.
- Wrackmeyer, Bernd,Ponomarev, Sergei V.
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p. 705 - 708
(2007/10/03)
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- Synthesis and dynamic properties of cycloheptatrienyl(dipropyl)borane. Equilibrium with 7-dipropylborylnorcaradiene
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The synthesis of cycloheptatrienyl(dipropyl)borane (2a) was accomplished via the exchange reaction of trimethyl(cycloheptatrienyl)tin (6) and dipropylchloroborane. Compound 2a was found by NMR spectroscopy to equilibrate with its valence tautomer 7-exo-(d
- Gridnev, Ilya D.
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p. 1034 - 1043
(2007/10/03)
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- Thermal decomposition of platinum(IV)-silicon, -germanium, and -tin complexes
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The thermal decomposition of a number of complexes of the type [PtMe2(Me3E)X(diimine)] (E = Si, Ge, Sn; X = Cl, Br, I) has been studied. The thermal stability of complexes, as determined by thermogravimetric analysis (TGA), varies depending on the diimine ligand in the order 2,2′-bipyridyl (bpy) > 4,4′-di-tert-butyl-2,2′-bipyridyl (bpy-tbu2) > N-(2-(dimethylamino)ethyl)pyridine-2-aldimine (paen-me2) > (2-imino-n-propyl)pyridine (py-n-pr). Stability also varies according to the trends E = Sn ≈ Ge > Si and X = I > Br > Cl. The products of thermal decomposition have also been determined by 1H NMR and three distinct modes of decomposition are evident: reductive elimination of Me3EX, reductive elimination of Me4E, and α-elimination of Me2E. The competition between reductive elimination of Me3EX and Me4E depends primarily on the halide, X, with the ratio Me3EX:Me4E highest for X = Cl and lowest for X = I. The competition between reductive elimination and α-elimination depends primarily on E, with the tendency to α-elimination of Me2E increasing as E = Si 2(Me3Si)(bpy)] as 233 ± 14 kJ mol-1.
- Levy, Christopher J.,Puddephatt, Richard J.
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p. 4115 - 4120
(2008/10/08)
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- Photoinduced Reactions of Tri-terf-butylindium with (Diethylamino)trimethylstannane and (Di-n-butylamino)trimethylstannane
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The preparations of [(t-Bu)2InNEt2]2 and [(t-Bu)2InN(n-Bu)2]2 by the photoinduced reactions of (t-Bu)3In with Et2NSnMe3 and (n-Bu)2NSnMe3, respectively, have been investigated. The isolation and characterization of products other than [(t-Bu)2InNE2]2 in these reactions clearly indicate that the reactions of (t-Bu)3In with R2-NSnMe3 do not proceed by simple alkyltrimethyltin elimination. A possible radical mechanism for the formation of the byproducts has been suggested. X-ray crystallographic studies indicate that both compounds are dimeric in the solid state. Crystallographic data: for [(t-Bu)2InNEt2]2 orthorhombic space group Pbca (No. 61), a = 19.135(7) A, b = 19.670(6) A, c = 15.793(7) A, V = 5944.41(5) A3 p(calcd) = 1.346 g cm-3; for [(t-Bu)2InN(n-Bu)2]2, triclinic space group P1 (No. 2), a = 11.943(2) A, b = 15.790(1) A, c = 10.711(3) A, α = 98.60-(1)°,β= 103.54(2)°, V = 94.85(1)°, V = 1926 A3 p(calcd) = 1.232 g cm-3. Mass spectrometry data indicate that both compounds exist as dimers in the gaseous state.
- Freeman, Daniel L.,Odom, Jerome D.,Rodger Nutt,Lebioda, Lukasz
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p. 2718 - 2722
(2008/10/09)
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- The X-Ray Structure Determination of tert-Butylimido Methylindane, [CH3In-NC(CH3)3]4
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The reaction of MeInCl2 iwth LiN(H)tBu in 1:2 molar ratio forms [MeIn-NtBu]4 in high yield, lithium chloride, and the free amine H2NtBu. The crystal structure of the imidomethylindane with cubic In4N4 skeleton has been determined.
- Schmid, K.,Kuehner, S.,Hausen, H.-D.,Weidlein, J.
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- Methyl metal(III)-nitrogen compounds with an oligocyclic as well as cage structures (MIII = Al, Ga, In)
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Tetrameric trimethylsilylimidomethylgallane, (MeGa=NSiMe3)4 (Me = CH3), is formed in ca. 60% yield by the reaction of Br2Ga-N(H)SiMe3 with lithium methanide in a 1:2 ratio. The high melting (278°C), volatile (MS), and even in the gas phase assoziated compound crystallizes in the monoclinic space group C2/c with the cell parameters a = 2001.0(4), b = 1011.6(2), c = 1932.2(4) pm, β = 120.13(2)°, and Z = 4 tetramers. The Ga4N4-skeleton is nearly a perfect cube with Ga-N bonds of 199 pm (average) and Ga-N-Ga angles of 90°. Diazadistannetidine, (Me2Sn=NtBu)2 (tBu=C(CH3)3) and AlMe3 (1:1) forms in toluene at 45-50°C tetramethylstannane and heterocyclic Me2Sn(NtBu)2AlMe. In solution and in the solid state a centrosymmetric dimer (point symmetry Ci) is formed (monoclinic space group P21/n, a = 1154.7(3), b = 921.17(12), c = 1463.9(3) pm, β = 101.08(2)°, and Z = 2 dimers). The relatively short Al-N (183.1(3) pm) and Sn-N (202.0(3) pm) distances in this tricyclic system have been used for a comparitive discussion of MIII-N bond lengths (MIII = Al, Ga, In). Therefore, the X-ray structure of the known Ga(N(SiMe3)2)3 has been re-investigated at -100°C. At least (MeIn=NtBu)4 has been prepared from (Me2Sn=NtBu)2 and base-free InMe3 (1:2 ratio) in toluene at 75-85°C. The NMR, ir, and Raman spectra are compared with the data of the corresponding Al and Ga homologues, respectively.
- Kuehner,Kuhnle,Hausen,Weidlein
-
-
- The chemistry of borylstannanes: Oxidative addition to palladium species and its application to palladium-catalyzed borylstannation of alkynes
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cis addition of the borylstannanes Me3SnB-[NMe(CH2CH2)NMe] (1) and Me3SnB(NEt2)2 (4) across alkynes was efficiently catalyzed at room temperature or 80°C by Pd(PPh3)4,
- Onozawa, Shun-Ya,Hatanaka, Yasuo,Sakakura, Toshiyasu,Shimada, Shigeru,Tanaka, Masato
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p. 5450 - 5452
(2008/10/09)
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- Synthesis of substituted aminogallanes by alkyltrimethyltin elimination
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Alkyltrimethyltin elimination reactions of R3Ga (R = Me, Et) with R″R′NSnMe3 (R″ = i-Bu, SnMe3, C6H11 and R′ = i-Bu, i-Pr, C6H11) have been investigated. The aminogallanes [Mesu
- Nutt, W. Rodger,Murray, Kelly J.,Gulick, James M.,Odom, Jerome D.,Ding, Yan,Lebioda, Lukasz
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p. 1728 - 1733
(2008/10/09)
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- Triorganotin(IV) derivatives of several 4-acyl-5-pyrazolonato ligands: Synthesis, spectroscopic characterization and behavior in solution crystal structure of aquotrimethyl(4-p-methoxybenzoyl-1-phenyl-3-methyl-pyrazolon-5-ato)tin(IV)
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New triorganotin(IV) derivatives [(Q)SnR3 · x(H2O)] (x = 0, R = Ph; x = 1, R = Me and nBu) (in general QH = 1-R′-3-methyl-4-R″ (C=O)-pyrazol-5-one; in detail Q′H: R′ = C6H5, R″ = C6H5; QAH: R′ = C6H5, R″ = p-CH3O-C6H4; QNH: R′ = C6H5, R″ = p-NO2-C6H4; QBrH: R′ = C6H5, R″ = p-Br-C6H4; Q″ H: R′ = C6H5, R″ = CH3; QClH: R′ = C6H5, R″ = CCl3; QFH: R′ = C6H5, R″ = CF3; QMH: R′ = CH3, R″ = C6H5; QDH: R′ = CH3, R″ = CH3) have been synthesized and characterized by analysis and spectral (IR and 1H, 13C and 119Sn NMR) data. The (Q)SnPh3 derivatives are five-coordinated in the solid state, with a likely skewed cis-trigonal bipyramidal (cis-TBP) geometry around the tin center and the ligand (Q)- acting in the bidentate form. In [(Q)SnR3 · (H2O)] derivatives (R = nBu or Me) a coordination site is occupied by water, with the ligand (Q)- coordinating in a monodentate fashion. The crystal structure of [(QA)SnMe3 · (H2O)] has been determined: the tin atom is found in a distorted TBP environment, with the methyls in the equatorial positions. Two of the Sn-C bond lengths are normal (2.11(1) and 2.08(2) A) whereas the third is longer (2.18(2) A); the ligand binds the metal atom through one carbonyl oxygen in the apical position (Sn-O = 2.10(1) A). The bond length between H2O and Sn is longer (2.41(2) A), and the O-Sn-O angle is 174.9(5)°. H atoms of water are involved in an intermolecular H-bond network with uncoordinated carbonyl and the pyridinic N atom of the ligand. In chloroform solution the [(Q)SnR3 · (H2O)] derivatives (R = Me or nBu) lost the molecule of water and adopt a tetrahedral arrangement. They also give rise to a slow disproportionation, yielding SnR4 and [(Q)2SnR2] derivatives.
- Marchetti, Fabio,Pettinari, Claudio,Cingolani, Augusto,Lobbia, Giancarlo Gioia,Cassetta, Alberto,Barba, Luisa
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p. 141 - 154
(2007/10/03)
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- Method for the synthesis of metal alkyls and metal aryls
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Method for forming metal alkyl compounds by the direct combination of metal halide, lithium metal, and alkyl or aryl halide and for purifying metal alkyl compounds by repeated sublimation/pumping cycles. The method can be used to produce metal alkyl compounds which are substantially free of volatile impurities.
- -
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-
- Trimethylstannyl- and Dimethylstannyl-substituted Pyrroles-Synthesis, Spectra, and Structures
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Monomeric trimethylstannyl pyrroles, Me3SnR (Me=CH3 and R=-NC4H4, -NC4H2Me2-2,5, -NC4Me4-2,3,4,5, -C4H3NMe-1), are synthesized by metathesis reactions from Me3SnCl with 1(N)- and 2(C)-lithiumpyrroles, respectively. An almost similar procedure gives monomeric dimethylstannylbis(pyrroles),Me2SnR2 (1a-3a), from Me2SnCl2 and 1-Li-pyrrolides (1:2 molar ratio) in good yields. Lithiated 1,2,5-trimethylpyrrole and Me3SnCl forms the com pound Me3Sn-CH2-C4H2Me(-5)NMe (8), the reaction of Me2SnCl2 with 2-lithium-1-methylpyrrole gives oligomeric [Me2Sn-C4H2NMe-]x, (6a). The mass-, NMR, and vibrational spectra have been measured and discussed. The results of the X-ray structure determinations of Me3Sn-NC4H4 (1) and Me2Sn(-NC4Me4)2 (3a) are compared with the structure of the known dimethylmetal pyrroles of Al, Ga, and In.
- Hillmann, J.,Hausen, H.-D.,Schwarz, W.,Weidlein, J.
-
-
- On the Role of the Solid-Gas Interface in the Thermolysis of Trimethylgermane and Trimethylstannane
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Metal film surfaces have a profound effect on the thermal decomposition of Me3MH (M = Ge and Sn), both of which unusually decompose by half-order kinetics at elevated temperature.
- Harrison, Philip G.,McManus, James,Podesta, David M.
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p. 291 - 293
(2007/10/02)
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- Some further studies on acyltrimethylstannanes
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The scope and limitations of the palladium-catalysed preparation of acyltins from ditins and acyl chlorides are discussed in detail.Preliminary studies on the chemistry of acyltrimethylstannanes are described.
- Mitchell, Terence N.,Kwetkat, Klaus
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p. 127 - 138
(2007/10/02)
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- Formation of organodilithium compounds via lithium-tin exchange
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The reaction of methyllithium in THF with 2,5-bis(trimethylstannyl)-1,5-hexadiene (6) affords 2,5-dilithio-1,5-hexadiene (2) via the intermediacy of lithium stannates. The similar reaction of (2Z,4Z)-2,5-bis(trimethylstannyl)-2,4-hexadiene (11) affords (2E,4E)-2,5-dilithio-2,4-hexadiene (3). The more favorable formation of 3 suggests a greater relative stability over 2. Ab initio calculations indicate that the symmetrical dilithium-bridged structure found for 3 is more favorable than the unsymmetrical dilithium-bridged structure found for 2.
- Ashe III, Arthur J.,Lohr, Lawrence L.,Al-Taweel, Samir M.
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p. 2424 - 2431
(2008/10/08)
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- Organometallic compounds of the lanthanides. 64. Synthesis and X-ray crystal structures of dimethylgermyl bis(tetramethylcyclopentadienyl) halide and alkyl derivatives of the lanthanides
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Metathesis of Me2GeCl2 or Me2SnCl2 with 2 equiv of LiC5Me4H affords Me2Ge(C5Me4H)2 (1) and Me2Sn(C5Me4H)2 (2), respectively. The subsequent deprotonation of 1 with MeLi yields only the desired dilithium salt Me2Ge(C5Me4Li)2 (3) whereas 2 forms Me4Sn and two LiC5Me4H. The trichlorides of neodymium, samarium, holmium, and lutetium react with the dilithium salt 3 with the formation of Me2Ge(C5Me4)2LnCl 2Li(THF)2 (Ln = Nd (4), Sm (5), Ho (6), Lu (7)). The reaction of 4 and 6 with LiCH(SiMe3)2 produces Me2Ge(C5Me4)2LnCH(SiMe 3)2 (Ln = Nd (8), Ho (9)). The new compounds have been characterized by elemental analysis, mass and NMR spectra, as well as X-ray structural analysis of 5, 7, and 9. The halides 5 and 7 crystallize in the monoclinic space group P21/c (No. 14) with a = 9.7284 (9), b = 19.397 (1), c = 16.610 (2) ?, β = 98.963 (9)°; Z = 4 or a = 9.578 (3), b = 19.218 (4), c = 16.525 (4) ?, β = 99.73 (2)°; Z = 4, respectively. Least-squares refinement led to a final R value of 0.020 (Fo > 4σ(Fo)) for 5554 independent reflections for 5 or of 0.028 (Fo > 3σ(Fo)) for 5822 independent reflections for 7. Compound 9 crystallizes in the monoclinic space group P21/m (No. 11) with a = 9.2621 (8), b = 14.216 (2), c = 11.839 (2) ?, β = 107.79 (1)°, Z = 2, and R = 0.023 (Fo > 4σ(Fo)) for 2954 reflections. The structure of 9 shows a short Ho-C (methyl) contact of 2.774 (4) ?.
- Schumann, Herbert,Esser, Lothar,Loebel, J?rg,Dietrich, Andreas,Van Der Helm, Dick,Ji, Xinhua
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p. 2585 - 2592
(2008/10/08)
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- Darstellung, Stereochemie und Reaktivitaet von Hydrido-Stannyl-Komplexen des Eisens und davon abgeleiteter anionischer Stannyl-Komplexe
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Octahedral hydrido stannyl complexes of iron can be prepared by three different routes: (i) mer-(CO)3(PPh3)Fe(H)SnR3 (1a,b) or cis,cis-(CO)2(dppe)Fe(H)SnR3 (1c,d) (R = Me, Ph) by treating the silyl complexes (CO)3(PPh3)Fe(H)SiMe3 or (CO)2(dppe)Fe(H)SiMe3
- Knorr, Michael,Piana, Hermann,Gilbert, Steffen,Schubert, Ulrich
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p. 327 - 350
(2007/10/02)
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- Preparation and properties of tris(trimethylstannyl)silyl complexes of chromium, molybdenum, and tungsten. X-ray structure of [NEt4][(CO)5WSi(SnMe3)3]
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Preparations of the silyl complexes [NEt4][(CO)5MSi(SnMe3)3] (M = Cr, [NEt4][1]; M = Mo, [NEt4][2]; M = W, [NEt4][3]) from [NEt4][(CO)5MCl] and (THF)3LiSi(SnMe3)3 are reported. Additionally, syntheses of Si(SnMe3)4 and (THF)3LiSi(SnMe3)3 are described. Attempts to cleave a Si-Sn bond in [NEt4][3] are discussed. Halogens I2 and ICl react with [NEt4][3] to yield [NEt4][(CO)5WI] and ISi(SnMe3)3 or ClSi(SnMe3)3, respectively. Two equivalents of HCl are necessary to effect complete conversion of [NEt4][3] to [NEt4][(CO)5WCl] and ClSi(SnMe3)3. No Si-Sn bond cleavage in [NEt4][3] is observed with Li or Na metal, sodium naphthalenide, NaOMe, LiBEt3H, or LiMe. The one-electron oxidants [Cp2Fe][FeCl4] and AgOTf react with [NEt4][3] to give uncharacterized solids. The complex [NEt4][3] crystallizes in the monoclinic space group P21/n, with a = 13.958 (4) ?, b = 18.501 (4) ?, c = 14.035 (4) ?, β = 94.96 (2)°, V = 3611 (2) ?3, and Z = 4. The W-Si bond is 2.652 (4) ?, slightly longer than the W-Si bond in the previously reported [PPN][(CO)5WSiMe3] (2.614 (2) ?).
- Heyn, Richard H.,Tilley, T. Don
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p. 4051 - 4055
(2008/10/08)
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- Organotin compounds. XI. Organotin hydride additions to various methyl dihydronaphthalenecarboxylates
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Free rdical hydrostannation of methyl 3,4-dihydronaphthalene-1-carboxylate (I), methyl 3,4-dihydronaphthalene-2-carboxylate (III), and methyl 1,4-dihydronaphthalene-2-carboxylate (V) with triorganotin hydrides, R3SnH (R = Me, n-Bu, Ph) gives the energetically unfavourable cis products, 2-triorganostannyl-1,2,3,4-tetrahydronaphthalene-1-carboxylate (II), 1-triorganostannyl-1,2,3,4-tetrahydronaphthalene-2-carboxylate (IV), and 3-triorganostannyl-1,2,3,4-tetrahydronaphthalene-2-carboxylate (VI) in high yields, via a trans addition of the tin hydrides.The hydride abstractions by the intermediate 2-, 1- and 3-triorganostannyl-1,2,3,4-tetrahydronaphthyl radicals (XI, XII and XIII respectively) take place stereospecifically and exclusively from the less-hindered ring side.The structures of the isomers II, IV, and VI, were established by (a) their transformation into the corresponding chlorodiorganostannyl derivatives VIII, IX, and X, which were shown spectroscopically to have cis stereochemistries by intramolecular complexation of the ester group, and (b) their NMR data.Full 1H, 13C, and 119Sn NMR data are given.
- Podesta, Julio C.,Ayala, Alicia D.,Chopa, Alicia B.,Giagante, Nelda N.
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-
- Alkyl Group Transfer from Rhodium(I) to Electrophilic Reagents; Inducement by a Tertiary Phosphine
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Although the compound RhMe(CO) (1) is normally inert to methyl iodide, chlorotrimethyltin and acetone, it reacts in the presence of trimethylphosphine with (a) methyl iodide to form the cationic complex >(+) (2), and methane, and ethylene but not ethane, (b) chlorotrimethyltin to form (2) and tetramethyltin, and (c) acetone to form (2) and t-butoxide; the role of the trimethylphosphine seems to involve substituting one arm of the triphosphine, thus rendering the Rh-Me moiety more reactive towards electrophilic reagents.
- Johnston, Gregory G.,Baird, Michael C.
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p. 1008 - 1009
(2007/10/02)
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- Synthesis, spectroscopic investigations, and molecular structures of 1-elementa-5-stannabicyclo[3.3.01,5]octanes, RR′Sn(CH2CH2CH2)2E (E = NMe, O, S)
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The 1-elementa-5-stannabicyclo[3.3.01,5]octanes Cl2Sn(CH2CH2CH2)2E (E = NMe, O, S), Me(Cl)Sn-(CH2CH2CH2)2E (E = NMe, O), Me2Sn(CH2CH2CH2)2E (E = NMe, O), and t-Bu2Sn(CH2CH2CH2)2NMe and the stannacyclooctane Me2Sn(CH2CH2CH2)2CH 2 have been prepared by the reaction of the Grignard reagents E(CH2CH2CH2MgX)2 (X = Cl, Br) with tin tetrachloride or organotin halides. The molecular structures of Cl2Sn(CH2CH2CH2)2NMe (1), Cl2Sn(CH2CH2CH2)2O (5), and Cl2Sn(CH2CH2CH2)2S (8) were determined by X-ray analysis. 1 crystallizes in the monoclinic space group Cc (Z = 4) with a = 13.987 (5) ?, b = 7.668 (2) ?, c = 11.213 (3) ?, and β = 112.68 (2)°. The structure was refined to R = 0.027. 5 crystallizes in the monoclinic space group C2/c (Z = 8) with a = 23.034 (7) ?, b = 7.153 (2) ?, c = 13.944 (4) ?, and β = 114.09 (2)°. The structure was refined to R = 0.163. 8 crystallizes in the monoclinic space group P21/a (Z = 4) with a = 11.521 (1) ?, b = 13.869 (3) ?, c = 6.894 (1) ?, and β = 109.57 (1)°. The structure was refined to R = 0.072. As a result of the Sn-N (2.441 ?), Sn-O (2.384 ?), and Sn-S (2.851 ?) interaction, respectively, the tin atoms in 1, 5, and 8 exhibit distorted trigonal-bipyramidal configurations with the heteroatom in apical position. 1H, 13C, and 119Sn NMR studies in solution show conformational equilibria with dominating boat-chair (BC) and chair-chain (CC) conformations. The dynamic behavior of the compounds is interpreted in terms of a combined dissociation-inversion (DI) and ring inversion (RI) mechanism.
- Jurkschat, Klaus,Schilling, J?rgen,Mügge, Clemens,Tzschach, Alfred,Meunier-Piret, Jacqueline,Van Meerssche, Maurice,Gielen, Marcel,Willem, Rudolph
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- Organotin compounds X. Organotin hydride addition to methyl cyclohexene-1-carboxylate and methyl indene-3-carboxylate
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Free radical hydrostannation of methyl cyclohexene-1-carboxylate (I) and methyl indene-3-carboxylate (III) with trialkyltin hydrides, R3SnH (R=Me, n-Bu, Ph) gives the energetically unfavourable cis products, 2-trialkylstannyl cyclohexanecarboxylate (II) 2-trialkylstannyl indene-1-carboxylate (IV) in high yields, via a trans addition of the thin hydrides.The hydride abstractions by the intermediate trialkylstannylcyclohexanyl (VIII) and trialkylstannylindanyl (IX) intermediate radicals take place stereospecifically, and exclusively from the less hindered ring side.The structures of the isomers II and IV were established by (a) their transformation into the corresponding chlorodialkylstannylderivatives V and VI, which were shown spectroscopically to have cis stereochemistries by intramolecular complexation of the ester group, and (b) their NMR data.Full 1H, 13C, and 119Sn NMR data are given.
- Ayala, A. D.,Giagante, N.,Podesta, J. C.,Neumann, W. P.
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p. 317 - 330
(2007/10/02)
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- Reactions of organotin hydrides with lithium diisopropylamide and organolithiums. Reactivities of the intermediates and of the lithium hydride produced
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Equimolar lithium diisopropylamide (LDA) and trimethyltin hydride (TMTH) react in tetrahydrofuran (THF) to form diisopropylamine and (trimethylstannyl)lithium, but in diethyl ether or hexanes 2 mol of TMTH is required for complete reaction and the products are diisopropylamine, hexamethylditin, and lithium hydride. When organic halides are present in this reacting system, reduction to alkane or substitution to form the trimethylalkyltin may occur depending on the nature of the halide. These and other observations suggest that (trimethylstannyl)lithium is formed as an intermediate yielding the tetraalkyltin. Studies on the products and stoichiometries of the reductions of alkyl bromides in ether and hexanes suggest that three reducing agents may be involved: TMTH, [Me3Sn(H)N-i-Pr2]-, and [Me3SnSn(H)Me3]-. The latter predominates in ether, and either or both of the others predominate in hexanes. Formation of methylcyclopentane from 1-bromo-5-hexene suggests involvement of a free radical mechanism. When methyllithium is used instead of LDA in the reaction with TMTH, the products are tetramethyltin and lithium hydride. This reaction can also be diverted to reduction by the presence of primary bromides. Aryl bromides react in both systems, but the yields of either substitution or reduction products are low. The lithium hydride formed in these reactions is extremely reactive as a base as shown by a brief study of its reaction with weak carbon acids and amines and as a nucleophile by its reaction with hexamethylditin to form (trimethylstannyl)lithium in THF.
- Reimann, Werner,Kuivila, Henry G.,Farah, Dan,Apoussidis, Theodorus
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p. 557 - 565
(2008/10/08)
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- DIE CHEMIE DER SCHWEREN CARBEN-ANALOGEN R2M, M=Si, Ge, Sn. X. 7-SILA-NORBORNADIENE: REAKTIONEN MIT HALOGENEN UND THERMOLYSE IN GEGENWART VON METALLORGANISCHEN ODER ORGANISCHEN HALOGENIDEN
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The 7-sila-norbornadienes (I-IV) react rapidly with halogens at -20 to +20 deg C to yield Me2SiHal2 (Hal=Cl, Br, I) and the naphthalene or benzene derivatives (V-VIII).Bromine in CCl4 at 0 deg C, however, caused surprising rearrangement in I giving the 2-bromosilylated naphthalene (IX), since an attack at the alkene group seemed to be preferred.Methylation and methoxylation of IX gave respectively X and XI.Careful hydrolysis of IX yielded the disiloxane XII.Insertions of Me2Si into the Si-Hal, Si-H, Si-C, or Sn-C bonds were not observed at 160-200 deg C, whereas insertions into Sn-Cl or Sn-H bonds occurred smoothly via a one-step mechanism.Halogen is abstracted from different C-Hal bonds leading to Me2SiHal2 and sometimes to Me4Si2Hal2.The degradation of the silylene precursors in these cases is always first order and resembles that of spontaneous thermolysis.
- Appler, Hubertus,Neumann, Wilhelm P.
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p. 247 - 260
(2007/10/02)
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- Electrophilic cleavages in (CH3)3SnCH2M(CH3)3 (M = Sn, Ge, Si, C). 1. Product distribution
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The extent to which Sn-CH2 and/or Sn-CH3 cleavage occurs in (CH3)3SnCH2M(CH3)3 (M = Sn, Ge, Si) in reactions with several electrophiles has been determined. With iodine and with
- Hawker, Darryl W.,Wells, Peter R.
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p. 821 - 825
(2008/10/08)
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- REACTIONS OF (CH3)3SnM(CH3)3 (M = Si; Ge) WITH CHLOROTRIMETHYLSTANNANE AND DICHLORODIMETHYLSTANNANE IN METHANOL SOLUTION
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The reactions of (CH3)3SnM(CH3)3 for M = Si and Ge with (CH3)3SnCl or (CH3)2SnCl2 in methanol follow the same path as the corresponding reactions of (CH3)6Sn2, and involve Sn-CH3 cleavage at essentially the same rate.Complications arise from reaction of H
- Cuthberston, Matthew J.,Wells, Peter R.
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- PROTOLYSES OF (CH3)3SnM(CH3)3 (M = Sn, Ge, SI, C)
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Product and kinetic studies on the reactions of hydrogen chloride in methanol solution with the substrates (CH3)3SnM(CH3)3 (M = Sn; Ge and Si) show that both Sn-M and Sn-CH3 cleavage reactions occur, at similar rates, and are followed by other reactions g
- Cuthberston, Matthew J.,Hawker, Darryl W.,Wells, Peter R.
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- DESULPHURIZATION OF SULPHUR-CONTAINING ORGANOMETALLIC COMPOUNDS
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Desulphurization reactions of trialkyl- and dialkyl-tin sulfides with a variety of reagents such as acyclic peroxides, salts and organic derivatives of some metals, halogen alkanes, as well as with sulphur acceptors such as copper powder or triphenylphosphine are discussed.
- Razuvaev, G.A.,Shcherbakov, V.I.,Grigor'Eva, I.K.
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p. 245 - 252
(2007/10/02)
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- FUNCTIONALLY SUBSTITUTED ORGANOTIN COMPOUNDS. II. IODODESTANNYLATION OF 1,1-BIS(TRIMETHYLSTANNYL)-1-ALKENES
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Treatment of 1,1-bis(trimethylstannyl)-1-alkenes with iodine gives mixtures of (E)- and (Z)-1-iodo-1-trimethylstannyl-1-alkenes, the ratio depending on the temperature used.Thermal and photochemical interconversion of these vinylic iodides has been observed.They cannot be used as precursors for the corresponding vinyl Grignard reagents, but undergo bromodestannylation to give the corresponding 1-bromo-1-iodo-1-alkenes.
- Mitchell, T. N.,Amamria, A.
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