1370439-84-1Relevant articles and documents
Effects of silyl substituents on the palladium-catalyzed asymmetric synthesis of axially chiral (allenylmethyl)silanes and their S E2′ chirality transfer reactions
Ogasawara, Masamichi,Ge, Yonghui,Okada, Atsushi,Takahashi, Tamotsu
, p. 1656 - 1663 (2012/04/23)
A series of axially chiral 4-substituted-1-silyl-2,3-butadienes [(allenylmethyl)silanes] were synthesized from 3-bromo-5-silylpenta-1,3-dienes by a Pd-catalyzed asymmetric reaction with a soft nucleophile. The optically active (allenylmethyl)silanes react with an acetal in the presence of TiCl 4 to give the enantiomerically enriched 1,3-diene derivatives through an SE2′ pathway. Effects of the silyl groups on the enantioselectivity of the asymmetric allene synthesis and the subsequent S E2′ chirality transfer reaction were studied. It was found that as the steric bulk of the silyl groups in the 3-bromo-5-silylpenta-1,3-dienes was increased from -SiMe3 to -SiiPr3, the enantioselectivity of the two enantioselective processes also improved.
