Enantioposition-selective alkynylation of biaryl ditriflates by palladium-catalyzed asymmetric cross-coupling
作者:Takashi Kamikawa、Yasuhiro Uozumi、Tamio Hayashi
DOI:10.1016/0040-4039(96)00517-5
日期:1996.4
Asymmetriccross-coupling of prochiral biaryl ditriflate, 1-[2,6-bis[[(trifluoromethyl)sulfonyl]oxy]phenyl]naphthalene (1) or 1,3-bis[[(trifluoromethyl)sulfonyl]oxy]-2-(biphenyl-2-yl)benzene (4) with triphenylsilylethynylmagnesium bromide in the presence of lithium bromide and 5 mol % of palladium catalyst, PdCl2[(S)-Alaphos], proceeded with high enantioposition selectivity to give high yields of the
Enantioselective synthesis of axially chiral sulfur-containing biaryl derivatives through the electrophilic sulfenylation of biaryl phenols has been achieved for the first time. This catalyticasymmetric system, which involves sequential desymmetrization and kinetic resolution, is enabled by a combination of a novel 3,3′-disubstituted BINOL-derived selenide catalyst and an achiral sulfonic acid. Control experiments
achieved with a silylium-ion-like silicon electrophile paired with a List-type imidodiphosphorimidate (IDPi). The initial enantioinduction of the desymmetrization is further enhanced by a downstream kineticresolution that kinetically selects the monosilylated minor enantiomer to form the corresponding bissilylated diol (see Scheme; TBS=tert-butyldimethylsilyl).
Brønsted Acid Catalyzed Asymmetric Silylation of Biaryl Diols
作者:Benjamin List、Jung Tae Han、Hui Zhou
DOI:10.1055/a-2100-1575
日期:2023.12
We report a Brønstedacidcatalyzed enantioselective silylation of biaryl diols with an allylsilane as a silicon source. This process enables facile access to enantioenriched biaryl silyl ethers with an axial stereogenicity. A control experiment supports a mechanism proceeding by desymmetrization followed by kinetic resolution.