Enantioposition-selective alkynylation of biaryl ditriflates by palladium-catalyzed asymmetric cross-coupling

Article abstract of DOI:10.1016/0040-4039(96)00517-5

Asymmetric cross-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 corresponding axially chiral monoalkynylated biaryls, 2a or 2d, of high enantiomeric purity (up to >99% ee).