- Exploring the Reactivity of Donor-Stabilized Phosphenium Cations: Lewis Acid-Catalyzed Reduction of Chlorophosphanes by Silanes
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Phosphane-stabilized phosphenium cations react with silanes to effect either reduction to primary or secondary phosphanes, or formation of P-P bonded species depending upon counteranion. This operates for in situ generated phosphenium cations, allowing catalytic reduction of P(III)-Cl bonds in the absence of strong reducing agents. Anion and substituent dependence studies have allowed insight into the competing mechanisms involved.
- Pearce, Kyle G.,Borys, Andryj M.,Clark, Ewan R.,Shepherd, Helena J.
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supporting information
p. 11530 - 11536
(2018/09/21)
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- Addition of a Cyclophosphine to Nitriles: An Inorganic Click Reaction Featuring Protio, Organo, and Main-Group Catalysis
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The addition of a cyclotriphosphine to a broad range of nitriles gives access to the first examples of free 1-aza-2,3,4-triphospholenes in a rapid, ambient temperature, one-pot, high-yield protocol. The reaction produces electron-rich heterocycles (four lone pairs) and features homoatomic σ-bond heterolysis, thereby combining the key features of the 1,3-dipolar cycloaddition chemistry of azides and cyclopropanes. Also reported is the first catalytic addition of P?P bonds to the C≡N bond. The coordination chemistry of the new heterocycles is explored.
- Chitnis, Saurabh S.,Sparkes, Hazel A.,Annibale, Vincent T.,Pridmore, Natalie E.,Oliver, Alex M.,Manners, Ian
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supporting information
p. 9536 - 9540
(2017/08/01)
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- Phosphenium-insertion and chloronium-addition reactions involving the cyclo-phosphanes (t-BuP)n (n≤3, 4)
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The transfer of a Ph2P+-moiety provided by Ph2PCl and chloronium-addition with PCl5 or PhICl2 to the cyclo-phosphanes (t-BuP)n (n≤3 (4), 4 (5)) were investigated. The reactions strongly depend on the presence of GaCl3 or Me3SiOTf as a halide abstracting reagent. The reaction of 4 with Ph2PCl and GaCl3 quantitatively yields cation [Ph2P(t-BuP)3]+ (6+) as a GaCl4 - salt. Using Me3SiOTf as a halide abstracting reagent leads to the ring expansion of (t-BuP)3 (4) to tetrameric (t-BuP)4 (5) and cation 6+ is only formed as a minor product. Chloronium addition employing the PCl5/GaCl3 or PhICl2/Me3SiOTf systems as Cl+-sources to 4 gives complex reaction mixtures. In contrast, the Cl+-addition to 5 gives cation [Cl(t-BuP)4]+ (8+) quantitatively when the system PCl5/GaCl3 is used. Utilising PhICl2 in the presence of Me3SiOTf gives t-BuPCl2 as the main product.
- Holthausen, Michael H.,Knackstedt, Dane,Burford, Neil,Weigand, Jan J.
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p. 1155 - 1162
(2013/10/22)
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- Facile synthesis of dibenzo-7λ3-phosphanorbornadiene derivatives using magnesium anthracene
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Unprotected dibenzo-7λ3-phosphanorbornadiene derivatives RPA (A = C14H10 or anthracene; R = tBu, dbabh = NA, HMDS = (Me3Si)2N, iPr2N) are synthesized by treatment of the corresponding phosphorus dichloride RPCl 2 with MgA·3THF, in cold THF (~20% to 30% isolated yields). Anthracene and the corresponding cyclic phosphane (RP)n form as coproducts. Characteristic NMR features of the RPA derivatives include a doublet near 4 ppm in their 1H NMR spectra and a triplet peak in the 175-212 ppm region of the 31P NMR spectrum (2J PH ~14 Hz). The X-ray structures of the AN-PA and (HMDS)PA derivatives are discussed. Thermolysis of RPA benzene-d6 solutions leads to anthracene extrusion. This process has a unimolecular kinetic profile for the iPr2NPA derivative. The 7-phosphanorbornene anti-iPr2NP(C6H8) could be synthesized (70% isolated yield) by thermolysis of iPr2NPA in 1,3-cyclohexadiene.
- Velian, Alexandra,Cummins, Christopher C.
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supporting information
p. 13978 - 13981
(2012/10/29)
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- Ditelluride-promoted diphosphene transfer from a cyclotriphosphane to 2,3-dimethylbutadiene: characterization of di(aryltelluro)diphosphanes
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The cleavage of tri-tert-butylcyclotriphosphane 1 with di(4-methylphenyl)ditelluride 2 leads to 1,2-di-tert-butyl-1.2-di(4-methylphenyltelluro)diphosphane 3 and tetra-tert-butylcyclotetraphosphane.When 1 is heated with 2 in the presence of 2,3-dimethylbutadiene, the diphosphene trapping product 1,2-di-tert-butyl-4,5-dimethyl-1,2-diphosphacyclohex-4-ene 5 can be detected.The salt elimination reaction of tert-butyldichlorophosphane with 4-methylphenyltellurotelluromagnesium bromide leads mainly to 3 and ditelluride 2.Tellurophosphane 6 and 1,2-di-tert-butyl-1,2-di(aryltelluro)diphosphanes 3. 7 (7 : aryl = 2,4,6-triisopropylphenyl) are available in fair yields from di-tert-butylchlorophosphane or 1,2-di-tert-butyl-1,2-dichlorodiphosphane with metal tellurolates.At 90 deg C with 2,3-dimethylbutadiene, 7 acts as a source of 1,2-di-tert-butyldiphosphene trapped as cycloadduct 5. - Keywords: cyclophosphanes / phosphorus-carbon heterocycles / cleavage of phosphorus-phosphorus bonds / di(aryltelluro) diphosphanes / diphosphene transfer.
- Meyer, H. U.,Severengiz, T.,Mont, W. W. du
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p. 691 - 694
(2007/10/02)
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- Contributions to the Chemistry of Phosphorus,184. - Existence and Properties of a Phosphinidenediphosphirane (R1P)2C=PR2
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The reaction of K(tBu)P-P(tBu)K with the (dichloromethylene)phosphane 2,4-tBu2-6-MeC6H2P=CCl2 (1) yields the first phosphinidenediphosphirane (tBuP)2C=P-(2,4-tBu2-6-Me-C6H2) (2).Further products are the cyclophosphanes (tBuP)n (n=3,4) as well as the phosp
- Baudler, Marianne,Simon, Joachim
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p. 281 - 286
(2007/10/02)
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- Contributions to the Chemistry of Phosphorus, 173. - Synthesis and Properties of the Diphosphiranimines (tBuP)2C=NR (R = 2,4-tBu2C6H3, 2-tBuC6H4)
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The reaction of K(tBu)P-P(tBu)K with isocyanide dichlorides yields the first diphosphiranimines (tBuP)2C=NR.Besides, the cyclophosphanes (tBuP)n (n = 3,4) and the two configurational isomers of the corresponding 1,3-diphosphetane-2,4-diimines are formed.N
- Baudler, Marianne,Simon, Joachim
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p. 421 - 424
(2007/10/02)
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- Contributions in the Chemistry of Phosphorus, 131. Synthesis and Properties of the Methylenediphosphiranes (t-BuP)2C = CR2 (R = H, Me, 4-ClC6H4)
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The first methylenediphoshiranes (diphosphamethylenecyclopropanes) (t-BuP)2C = CH2 (1), (t-BuP)2C = CMe2 (2), and (t-BuP)2C = C(4-ClC6H4)2 (3) were synthesized by cyclocondensation of K(t-Bu)P - P(t-Bu)K with the corresponding 1,1-dichloroolefins.The homocyclophosphanes (t-BuP)n (n = 4,3) and in the case of 1 mainly H(t-Bu)P - P(t-Bu)H are formed as by-products.The three-membered heterocycles 2 and 3 could be purely isolated as surprisingly stable compounds.According to an X-ray single-crystal analysis 3 possesses approximately C2 symmetry and exhibits one of the smallest bonding angles φ (P - P - C) = 52.4 deg on a phosphorus atom experimentally proved so far.Along there are canals filled with disordered n-pentane molecules.
- Baudler, Marianne,Saykowski, Franz,Hintze, Michael,Tebbe, Karl-Friedrich,Heinlein, Thomas,et al.
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p. 1542 - 1550
(2007/10/02)
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