- Geometric E→Z Isomerisation of Alkenyl Silanes by Selective Energy Transfer Catalysis: Stereodivergent Synthesis of Triarylethylenes via a Formal anti-Metallometallation
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An efficient geometrical E→Z isomerisation of alkenyl silanes is disclosed via selective energy transfer using an inexpensive organic sensitiser. Characterised by operational simplicity, short reaction times (2 h), and broad substrate tolerance, the reaction displays high selectivity for trisubstituted systems (Z/E up to 95:5). In contrast to thermal activation, directionality results from deconjugation of the π-system in the Z-isomer due to A1,3-strain thereby inhibiting re-activation. The structural importance of the β-substituent logically prompted an investigation of mixed bis-nucleophiles (Si, Sn, B). These versatile linchpins also undergo facile isomerisation, thereby enabling a formal anti-metallometallation. Mechanistic interrogation, supported by a theoretical investigation, is disclosed together with application of the products to the stereospecific synthesis of biologically relevant target structures.
- Fa?bender, Svenja I.,Molloy, John J.,Mück-Lichtenfeld, Christian,Gilmour, Ryan
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p. 18619 - 18626
(2019/11/16)
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- Synthesis of an [(NHC)2Pd(SiMe3)2] complex and catalytic cis-bis(silyl)ations of alkynes with unactivated disilanes
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The novel complex cis-[(ITMe)2Pd(SiMe3)2 (ITMe=1,3,4,5-tetramethylimidazol-2-ylidene) has been synthesized by mild oxidative cleavage of Me3SiSiMe3 using [(ITMe)2Pd0]. The use of this complex as precatalyst for the cis-bis(silyl)ation of alkynes using unactivated disilanes is reported. Double the Si: The novel complex cis-[(ITMe)2Pd(SiMe3)2] (1, ITMe=1,3,4,5-tetramethylimidazol-2-ylidene) has been synthesized by mild oxidative cleavage of Me3SiSiMe3 using [(ITMe)2Pd0]. The synthesized complex was used as a precatalyst for the cis-bis(silyl)ation of alkynes using unactivated disilanes.
- Ansell, Melvyn B.,Roberts, Debbie E.,Cloke, F. Geoffrey N.,Navarro, Oscar,Spencer, John
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supporting information
p. 5579 - 5582
(2015/09/21)
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- Highly Efficient Palladium Catalysed System for Insertion of Acetylenes into Si-Si-Bonds. A New Method for Modification of Silicon-containing Polymers
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The Pd(dba)2-2P(OCH2)3CEt (dba = dibenzylideneacetone) system exhibited highly efficient catalysis in the insertion of acetylenes into Si-Si bonds of hexamethyldisilane, octamethyltrisilane, poly, poly(disilanylene)ethylene>, and
- Yamashita, Hiroshi,Catellani, Marta,Tanaka, Masato
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p. 241 - 244
(2007/10/02)
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- Formation and Reactions of Olefins with Vicinal Silyl and Stannyl Substituents
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The silicon-tin bond in Me3SiSnR3 (R=Me, n-Bu) adds regio- and stereospecifically to 1-alkynes and also to a limited number of nonterminal alkynes when Pd(PPh3)4 is added as a catalyst.The use of the (Z)-silylstannylalkenes thus formed in synthesis either
- Mitchell, T. N.,Wickenkamp, R.,Amamria, A.,Dicke, R.,Schneider, U.
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p. 4868 - 4874
(2007/10/02)
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- REACTION OF DISILANES WITH ACETYLENES. I. STEREOSELECTIVE ADDITION OF METHOXYMETHYLDISILANES TO PHENYLACETYLENE CATALYZED BY GROUP-VIII METAL PHOSPHINE COMPLEXES
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Addition reactions of methoxymethyldisilanes to phenylacetylene in the presence of various triphenylphosphine complexes of Ni, Rh, Pd and Pt were investigated.Palladium and platinum complexes, Pd(PPh3)4, PdCl2(PPh3)2 and Pt(PPh3)4 were found to be effecti
- Watanabe, Hamao,Kobayashi, Mitsunobu,Higuchi, Kazuaki,Nagai, Yoichiro
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