We report that transition metal-catalyzed nucleophilic activation can be combined with chiral amine-catalyzed iminium activation as exemplified by the unprecedented enantioselectiveconjugateaddition of a dimethylsilanyl group to α,β-unsaturatedaldehydes. These reactions proceed with excellent 1,4-selectivity to afford the corresponding β-silyl aldehyde products 3 in high yields and up to 97:3 er
Enantioselective Synthesis of α-Tri- and α-Tetrasubstituted Allylsilanes by Copper-Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Silylboronates
作者:Momotaro Takeda、Ryo Shintani、Tamio Hayashi
DOI:10.1021/jo400888b
日期:2013.5.17
copper/N-heterocyclic carbene-catalyzed asymmetric allylic substitution of allylphosphates with a silylboronate has been developed to give highly enantioenriched allylsilanes. High regioselectivity has been achieved by employing NaOH as the base, and this catalyst system is effective for both γ-mono- and disubstituted allylphosphates.