- An open-shell spin singlet copper-nitrene intermediate binding redoxinnocent metal ions: Influence of the Lewis acidity of the metal ions on spectroscopic and reactivity properties
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The yield of the Lewis acid adducts of a copper-tosylnitrene intermediate and their decay are dependent on the Lewis acidity of the redox innocent metal ions. Surprisingly, however, their spectroscopic properties and reactivity in nitrene transfer reaction with PPh3 are independent of the nature of the Lewis acid used. The result provides some new insights into the structure and reactivity of the Lewis-acid bound copper nitrene complexes.
- Monte-Prez, Ins,Kundu, Subrata,Ray, Kallol
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- A Dicopper Nitrenoid by Oxidation of a CuICuICore: Synthesis, Electronic Structure, and Reactivity
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A dicopper nitrenoid complex was prepared by formal oxidative addition of the nitrenoid fragment to a dicopper(I) center by reaction with the iminoiodinane PhINTs (Ts = tosylate). This nitrenoid complex, (DPFN)Cu2(μ-NTs)[NTf2]2 (DPFN = 2,7-bis(fluorodi(2-pyridyl)methyl)-1,8-naphthyridine), is a powerful H atom abstractor that reacts with a range of strong C-H bonds to form a mixed-valence Cu(I)/Cu(II) μ-NHTs amido complex in the first example of a clean H atom transfer to a dicopper nitrenoid core. In line with this reactivity, DFT calculations reveal that the nitrenoid is best described as an iminyl (NR radical anion) complex. The nitrenoid was trapped by the addition of water to form a mixed-donor hydroxo/amido dicopper(II) complex, which was independently obtained by reaction of a Cu2(μ-OH)2 complex with an amine through a protonolysis pathway. This mixed-donor complex is an analogue for the proposed intermediate in copper-catalyzed Chan-Evans-Lam coupling, which proceeds via C-X (X = N or O) bond formation. Treatment of the dicopper(II) mixed donor complex with MgPh2(THF)2 resulted in generation of a mixture that includes both phenol and a previously reported dicopper(I) bridging phenyl complex, illustrating that both reduction of dicopper(II) to dicopper(I) and concomitant C-X bond formation are feasible.
- Desnoyer, Addison N.,Nicolay, Amélie,Ziegler, Micah S.,Lakshmi,Cundari, Thomas R.,Tilley, T. Don
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- Construction of benzo-1,2,3-thiazaphosphole heterocycles by annulations of ortho-phosphinoarenesulfonyl fluorides with trimethylsilyl azide
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Annulations of ortho-phosphinoarenesulfonyl fluorides with trimethylsilyl azide were developed to access an unprecedented benzo-1,2,3-thiazaphosphole heterocycle. A corresponding reaction mechanism was proposed and further elucidated by experimental and computational studies. The reaction proceeds through a Staudinger-type iminophosphorane intermediate followed by intramolecular trapping with sulfonyl fluoride.
- Luo, Wenjun,Wang, Zhenguo,Cao, Xiaohui,Liang, Dacheng,Wei, Mingjie,Yin, Keshu,Li, Le
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- Palladium-Catalyzed Stereoselective Hydrodefluorination of Tetrasubstituted gem-Difluoroalkenes
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A highly stereoselective palladium(0)-catalyzed hydrodefluorination (HDF) of tetrasubstituted gem-difluoroalkenes is developed. By using catalytic Pd(PPh3)4 (2.5-5 mol percent) and hydrosilane Me2PhSiH, various trisubstituted terminal (E)-monofluoroalkenes can be synthesized with excellent E/Z selectivity (>99:1) and good functional group tolerability. The key stereocontrol should be exerted by an ester-directed C-F bond oxidative addition step in the catalytic cycle.
- Ma, Qiao,Liu, Caroline,Tsui, Gavin Chit
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supporting information
p. 5193 - 5197
(2020/07/04)
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- Sulfonylimino group transfer reaction using imino-λ3-iodanes with I2 as catalyst under metal-free conditions
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A new practical procedure of imination for sulfide has been developed. The treatment of (N-tosylimino)-phenyl-λ3-iodane, PhINTs, with various sulfides in the presence of a catalytic amount of I2 under metal-free conditions affords the corresponding N-tosylsulfilimine compounds with moderate to good yields. This facile transfer procedure of the sulfonylimino group can also be applied to triphenylphosphine to produce the respective iminotriphenylphosphoranes in high yields. According to the reaction mechanism studies, the process of imination from (N-tosylimino)-phenyl-λ3-iodane to sulfide under the conditions may involve radical steps within the reaction mechanism.
- Yoshimura, Akira,Makitalo, Cody L.,Jarvi, Melissa E.,Shea, Michael T.,Postnikov, Pavel S.,Rohde, Gregory T.,Zhdankin, Viktor V.,Saito, Akio,Yusubov, Mekhman S.
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- Designed To React: Terminal Copper Nitrenes and Their Application in Catalytic C?H Aminations
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Heteroscorpionate ligands of the bis(pyrazolyl)methane family have been applied in the stabilisation of terminal copper tosyl nitrenes. These species are highly active intermediates in the copper-catalysed direct C?H amination and nitrene transfer. Novel perfluoroalkyl-pyrazolyl- and pyridinyl-containing ligands were synthesized to coordinate to a reactive copper nitrene centre. Four distinct copper tosyl nitrenes were prepared at low temperatures by the reaction with SO2tBuPhINTs and copper(I) acetonitrile complexes. Their stoichiometric reactivity has been elucidated regarding the imination of phosphines and the aziridination of styrenes. The formation and thermal decay of the copper nitrenes were investigated by UV/Vis spectroscopy of the highly coloured species. Additionally, the compounds were studied by cryo-UHR-ESI mass spectrometry and DFT calculations. In addition, a mild catalytic procedure has been developed where the copper nitrene precursors enable the C?H amination of cyclohexane and toluene and the aziridination of styrenes.
- Moegling, Julian,Hoffmann, Alexander,Thomas, Fabian,Orth, Nicole,Liebh?user, Patricia,Herber, Ulrich,Rampmaier, Robert,Stanek, Julia,Fink, Gerhard,Ivanovi?-Burmazovi?, Ivana,Herres-Pawlis, Sonja
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supporting information
p. 9154 - 9159
(2018/07/25)
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- A cobalt(ii) iminoiodane complex and its scandium adduct: Mechanistic promiscuity in hydrogen atom abstraction reactions
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In addition to oxometal [Mn+O] and imidometal [Mn+NR] units, transient metal-iodosylarene [M(n-2)+-OIPh] and metal-iminoiodane [M(n-2)+-N(R)IPh] adducts are often invoked as a possible second oxidant responsible for the oxo and imido group transfer reactivity. Although a few metal-iodosylarene adducts have been recently isolated and/or spectroscopically characterized, metal-iminoiodane adducts have remained elusive. Herein, we provide UV-Vis, EPR, NMR, XAS and DFT evidence supporting the formation of a metal-iminoiodane complex 2 and its scandium adduct 2-Sc. 2 and 2-Sc are reactive toward substrates in the hydrogen-atom and nitrene transfer reactions, which confirm their potential as active oxidants in metal-catalyzed oxidative transformations. Oxidation of para-substituted 2,6-di-tert-butylphenols by 2 and 2-Sc can occur by both coupled and uncoupled proton and electron transfer mechanisms; the exact mechanism depends on the nature of the para substituent.
- Kundu, Subrata,Chernev, Petko,Engelmann, Xenia,Chung, Chan Siu,Dau, Holger,Bill, Eckhard,England, Jason,Nam, Wonwoo,Ray, Kallol
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supporting information
p. 14538 - 14543
(2016/09/28)
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- Zinc chloride catalyzed ring opening of N-arylsulfonyl aziridines by thioamides: A new approach to the synthesis of amidines
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The first zinc chloride catalyzed ring opening of N-arylsulfonyl aziridines by thioamides is described. Various thioamides were reacted with N-arylsulfonyl aziridines in the presence of a catalytic amount of dry zinc chloride to provide the corresponding
- Hajibabaei, Khadijeh,Zali-Boeini, Hassan
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supporting information
p. 2044 - 2048
(2014/11/08)
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- Chemoselectivity in coupling of azides with thioacids in solution-phase and solvent-free conditions
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Solvent-free rapid coupling of monothiocarboxylic acid with azide affords carboxamide chemoselectively. Triphenyl phosphine included as an additive influences the chemoselectivity, yielding carboxamide and thioamide. Similar variation in the chemoselectivity is observed in the absence and presence of triphenyl phosphine in solution-phase methodology. Rapidity and ecofriendliness of the solvent-free approach to yield the products in just 15min is noteworthy compared to the solution-phase protocol, which has a long reaction time (1-3 days).
- Nagarajan, Sangaraiah,Shanmugavelan, Poovan,Sathishkumar, Murugan,Priyadharshini, Namachivayam,Sudakar, Padmanaban,Ponnuswamy, Alagusundaram
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p. 668 - 680
(2013/01/15)
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- A facile noncatalytic pathway for the nitrene transfer process: Expeditious access to aziridines
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A fast and efficient method has been developed for generation of sulfonyl nitrene from N,N-dibromo-p-toluenesulfonamide (TsNBr2) in the presence of a base without any catalyst. This method was applied to produce aziridines from different kinds of olefins within a short time in high yields. The Royal Society of Chemistry.
- Saikia, Indranirekha,Kashyap, Bishwapran,Phukan, Prodeep
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supporting information; experimental part
p. 2967 - 2969
(2011/04/24)
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- O-alkoxyphenyliminoiodanes: Highly efficient reagents for the catalytic aziridination of alkenes and the metal-free amination of organic substrates
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Efficient nitrene precursors: Highly reactive iminoiodane-based nitrene precursors were prepared from ortho-alkoxyiodobenzenes. Owing to the presence of the ortho-substituent on the phenyl ring, these new iminoiodanes have excellent solubility in organic
- Yoshimura, Akira,Nemykin, Victor N.,Zhdankin, Viktor V.
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supporting information; experimental part
p. 10538 - 10541
(2011/11/12)
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- Comparison of the reactivity of N-(p-toluenesulfonyl)-sulfinimidoyl fluorides and chlorides toward triphenylphosphine
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The path of the reaction of aryl-N-(p-toluenesulfonyl)-sulfinimidoyl fluorides and triphenylphosphine is highly dependent on the order of the reactants addition. Addition of triphenylphosphine to aryl-N-(p-toluenesulfonyl) -sulfinimidoyl fluorides results in the formation of triphenyl(arylthio) phosphonium salts of N,N′-bis(p-toluenesulfonyl)aryl-sulfinamidines and triphenyldifluorophosphorane. By changing the reagent addition order, we obtained triphenyldifluorophosphorane, P, P, P-triphenyl- N- (p-toluenesulfonyl)-phosphine imide, and diaryl disulfides. The outcome of the reaction aryl-N-(arenesulfonyl)-sulfinimidoyl chlorides and triphenylphosphine does not depend on the order of addition of the reactants. P,P,P-Triphenyl-N- (arenesulfonyl)-phosphine imides, triphenyldichlorophosphorane, and diaryl disulfides were formed as a result.
- Pashinnik, Valeriy E.,Borovikov, Alexei V.,Shermolovich, Yuriy G.
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- Generation of nitrene by the photolysis of N-substituted iminodibenzothiophene
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(Chemical Equation Presented) To evaluate the ability of dibenzothiophene N-substituted sulfilimines as photochemical nitrene sources, their photolyses in the presence of several trapping reagents, such as sulfides, olefins, and phosphorus compounds, were performed. In the reactions, the corresponding imino-transfer compounds, namely sulfilimines, aziridines, and iminophosphoranes, were formed in good yields, indicating dibenzothiophene N-tosyl and N-acylsulfilimines have a potent nature as nitrogen sources.
- Morita, Hiroyuki,Tatami, Atsushi,Maeda, Tetsuo,Byung, Ju Kim,Kawashima, Wataru,Yoshimura, Toshiaki,Abe, Hitoshi,Akasaka, Takeshi
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supporting information; experimental part
p. 7159 - 7163
(2009/04/18)
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- An easy one-pot procedure for the synthesis of N-sulfonyl phosphorous ylides and sulfonyl iminophosphoranes
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Reaction of triphenylphosphine and an electron deficient acetylenic ester in the presence of strong N-H acid such as alkyl and aryl sulfamides or acetamide produces phosphorous ylides at room temperature in CH 2Cl2. The aryl sulfamide phosphoranes undergo a smooth transformation reaction in boiling toluene and produce iminophosphoranes. Springer-Verlag 2007.
- Shaabani, Ahmad,Rahmati, Abbas,Naderi, Soheila
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p. 553 - 557
(2008/02/03)
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- Synthesis of sulfur-containing aryliminophosphoranes
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Stabilized phosphoranes, obtained from the three-component reaction between dialkyl acetylenedicarboxylates and arylsulfonamides in the presence of triphenylphosphine, undergo a smooth intramolecular reaction, in boiling toluene to produce sulfur-containing iminophosphoranes in excellent yields.
- Yavari, Issa,Zabarjad-Shiraz, Nader,Bijanzadeh, Hamid R.
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p. 1381 - 1386
(2007/10/03)
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- Hypervalent iodine in synthesis XXXI: Formation of phosphinimines and arsinimines by nitrene route or non-nitrene route
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N-sulfonyltriphenylphosphinimines and N-sulfonyltriphenylarsinimines are prepared by the reaction of triphenylphosphine or triphenylarsine under nitrene-producing conditions with I-N ylide (PhI=NSO2R). Triphenylarsinimines can also be generated by a non-nitrene route from triphenylarsine, iodobenzene diacetate, and sulfonamides via triphenylarsine diacetate, Ph3As(OAc)2.
- Ou, Wei,Wang, Zhi-Gang,Chen, Zhen-Chu
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p. 2301 - 2309
(2007/10/03)
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- NEW SYNTHETIC APPLICATIONS OF METALLATED YLIDS
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The reaction of diylids 1 toward carbonates, carbamates, thiocarbamates, isocyanates, carbodiimides and sulfinates allow the quantitative preparation of functional Wittig reagents, which can be used in situ in the E-stereoselective synthesis of the corresponding α,β-unsaturated derivatives of carboxylic (or sulfinic) acids. The diylids 2 or yldiid 3 can be used as synthetic equivalents of RNH2- or NH2- anions and allow normal or functional alkylation of the nitrogen atom.
- Cristau, Henri-Jean,Perraud, Anne,Manginot, Eric,Torreilles, Eliane
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- PHOSPHONIUM AZA-YLDIID AS REAGENT FOR ONE-POT SYNTHESIS OF PHOSPHINIMINES WITH FUNCTIONAL N-SUBSTITUENTS.
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A new procedure for the one-pot synthesis of phosphinimines with functional N-substituents using the alkylation of phosphonium aza-yldiid 1 with α-bromo esters or the direct introduction of phosphorus and sulfur groups.
- Cristeau, Henri-Jean,Manginot, Eric,Torreilles, Eliane
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p. 347 - 350
(2007/10/02)
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- Reactions of cobaltacyclopentadiene complexes with organic azides directed toward synthesis of highly substituted pyrroles
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The reactions of the cobaltacyclopentadiene complexes (η5-C5H5)(PPH3)-Co(-CR1=CR2-CR3=CR4)- (I) with organic azides were investigated.The complex Ia (R1)=R2=R3=R4=Ph) reacts with phenyl azide at 80 degC to give 1,2,3,4,5-pentaphenylpyrrole in 73percent yeld.Similarly, the reactions of Ia with benzoyl and t-butoxycarbonyl azides give 1-benzoyl- and 1-(t-butoxycarbonyl)-2,3,4,5-tetraphenylpyrroles in 41 and 64percent yields, respectively, but reaction with p-toluenesulfonyl azide gives 2,3,4,5-tetraphenylpyrrole and 3,4,5,6-tetraphenylpyridazine in 35 and 45percent yields, respectively, in place of the expected 1-(p-toluenesulfonyl)-2,3,4,5-tetraphenylpyrrole.The reaction of Ic (R1=R4=Ph, R2=R3=CO2CH3) with phenyl azide at 130 degC gives 1,2,5-triphenyl-3,4-bis(methoxycarbonyl)pyrrole (IIc)and 2,5-diphenyl-3,4-bis(methoxcarbonylpyrrole (Vb) in 22 and 15percent yields, respectively.The reaction of Ic with benzenesulfonyl azide gives only Vb in 57percent yield.In the reaction of Id (R1=R3=Ph, R2=R4=CO2CH3) with benzenesulfonyl azide, Vb was unexpectedly obtained in 26percent yield, together with 2,4-diphenyl-3,5-bis(methoxycarbonyl)pyrrole (Vc, 30percent), which suggests that a skeletal rearrangement of the metallacycle IXd to IXc occurs during the reaction.The reaction of Ic or Id with benzoyl azide at 130 degC gives the 2(1H)-pyridinone derivatives VIIIa (82percent) and VIIIb (53percent), which are the products of the reaction of the corresponding cobaltacyclpentadiene with phenyl isocyanate generated by the rearrangement of benzoyl nitrene, in place of the expected, corresponding pyrrole.
- Hong, Pangbu,Yamazaki, Hiroshi
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p. 133 - 142
(2007/10/02)
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- The Wittig-type Reaction of O=C-, C=C, and N=C-Substituted Methylenetriphenylphosphoranes with N-Sulfinyl-p-toluenesulfonamide. An Intramolecular 1,3-Dipolar Cyclization of Imidoyl-conjugated Thione S-Imides
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The Wittig-type reactions of N-sulfinyl-p-toluenesulfonamide with (1) O=C-, (2) C=C-, and (3) N=C-cojugated phosphorus ylides were investigated.In the reaction with (1), N-sulfinyl-p-toluenesulfonamide reacted at both the ylide and the carbonyl moiety to form TsN=C-conjugated thione S-imide, which underwent intramolecular 1,3-dipolar cycloaddition of the CSN group with the aromatic C=C bond of the tosyl group giving a structurally unique spiro-fused tricyclic adduct.The structure of the adduct was determined by means of X-ray diffraction.In the reactions with (2) and (3), 1-azadiene and sulfobetaines were obtained instead of the expected conjugated thione S-imides.
- Saito, Takao,Nakane, Michio,Watanabe, Toshihiko,Motoki, Shinichi,Kobayashi, Kimiko,Sakurai, Tosio
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p. 2882 - 2888
(2007/10/02)
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- Synthesis of N-Acyl-, N-Sulfonyl-, and N-Phosphinylphospha-λ5-azenes by a Redox-Condensation Reaction Using Amides, Triphenylphosphine, and Diethyl Azodicarboxylate
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The reaction of phosphines and amides with diethyl azodicarboxylate (DAD) produced phospha-λ5-azenes.Thus aromatic amides and those aliphathic amides with electron-withdrawing substituents gave N-acyl-P,P,P-triphenylphospha-λ5-azenes (5) when triphenylphosphine (TPP) was employed.Both aryl- and alkylsulfonamides reacted with TPP and DAD to produce the N-sulfonylphospha-λ5-azenes (9).Diphenylphosphinamide (10) and ethyl carbamate (12) also produced the respective phosphazenes (11 and 13) with TPP and DAD.Secondary carboxamides and sulfonamides did not react with TPP and DAD.The reaction of triethyl phosphite with sulfonamides in the presence of DAD produced the phosphorimidates (20) in an analogous reaction, along with the corresponding N,N-diethylsulfonamides and the deethylated adduct of triethyl phosphite and DAD (23).Triethyl phosphite-DAD failed, however, to give a phosphorimidate with carboxamides but gave, instead, the rearranged adduct of DAD and triethyl phosphite (19).Tris(dimethylamino)phosphine reacted with sulfonamides and DAD but the products were the corresponding ethyl N-sulfonylcarbamates (26) rather than the phosphazenes.Tris(dimethylamino)phosphine reacted with azodicarbonamide (a molecule which contains both the azo and carboxamide groups) with the production of N,N-dimethylurea, again without formation of the phosphazene.Finally, the reaction of triphenylarsine with benzenesulfonamide and DAD produced N-(phenylsulfonyl)triphenylarsa-λ5-azene (30) but triphenylstibene with DAD and benzenesulfonamide only gave triphenylstibene oxide.Mechanistic possibilities for these reactions are also discussed.
- Bittner, Shmuel,Assaf, Yonit,Krief, Penina,Pomerantz, Martin,Ziemnicka, Barbara T.,Smith, Christina G.
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p. 1712 - 1718
(2007/10/02)
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- PREPARATION OF TETRAALKYLAMMONIUM N-CHLORO-p-TOLUENESULFONAMIDES AND THEIR APPLICATION TO IMINATION OF PHOSPHORUS COMPOUNDS AND SULFIDES.
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Tetraalkylammonium N-chloro-p-toluenesulfonamides were prepared from chloramine T and tetraalkylammonium chlorides as a substance corresponding to anhydrous chloramine T, and found to give rise to the effective tosylimination of phosphorus compounds and d
- Yamamoto,Yoshida,Hojyo,Terauchi
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p. 3341 - 3342
(2007/10/02)
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- PREPARATION AND REACTION OF N-TOSYL- AND N-ACYLSELENILIMINES
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N-Tosyl-Se,Se-diphenylselenilimines (Ia, hydrate state (Ib) of Ia), N-tosyl-Se-methyl-Se-phenylselenilimines (Ic), N-tosyl-Se,Se-dialkylselenilimines (Id-f), N-acyl-Se-aryl-Se-phenyl-selenilimines (IIa-e) and N-acyl-Se,Se-dibenzylselenilimine (IIf) were prepared.The pyrolyses of selenilimines (Ia, d, e, IIa-e) proceeded more readily than those of the corresponding sulfur derivatives.The pyrolyses of N-acyl-Se-aryl-Se-phenylselenilimines gave the corresponding isocyanates in good yields after treatment of the reaction mixture with aniline, together with aryl phenyl selenide.A ki netic study revealed that the rate of pyrolysis of N-benzoyl-Se,Se-diphenylselenilimine (IIa) was 300 times faster than that of the corresponding sulfilimine.The activation enthalpy and entropy were ΔH* = 32.1 kcal/mol and ΔS* = 1.2 e.u. respectively for Ph2Se -> NCOPh.Oxidations of N-tosyl- and N-benzoyl-Se,Se-diphenylselenilimine were carried out with hydrogen peroxide or potassium permanganate to obtain the corresponding selenoxides or selenones, respectively.Hydrolysis of N-tosyl- and N-benzoyl-Se,Se-diphenylselenilimines also took place more readily than that of the corresponding sulfilimines and the selenoxides and the amides were obtained in good yields at room temperature.When N-tosyl-Se,Se-pentamethyleneselenilimine (Ie) was treted with conc. sulfuric acid, a selenurane, Se-hydroxy-Se-(hydroxysulfoxy)selenane (III) was obtained in a high yield.
- Oae, Shigeru,Fukumura, Mitsuo,Furukawa, Naomichi
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p. 153 - 162
(2007/10/02)
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