Base-Accelerated Enantioselective Substitution of Morita-Baylis-Hillman Carbonates with Dialkyl Phosphine Oxides

A base could accelerate the S(N)2' or S(N)2' S(N)2' reaction of Morita-Baylis-Hillman (MBH) carbonates with dialkyl phosphine oxides, but the judicial choice of an appropriate base would greatly depress this competitive S(N)2' reaction and allow for a highly enantioselective allylic substitution reaction with satisfactory yields and excellent enantioselectivities.