Base-catalyzed diastereodivergent thia-Michael addition to chiral beta-trifluoromethyl-alpha,beta-unsaturated N-acylated oxazolidin-2-ones

Base-catalyzed diastereodivergent thia-Michael addition of thiols to chiral beta-trifluoromethyl-alpha,beta-unsaturated N-acylated oxazolidin-2-ones is reported. By tuning the base-catalyst (i-Pr2NEt, DABCO, or P-2-t-Bu), a range of chiral thia-Michael adducts was synthesized in good yields with high diastereo-selectivities. A plausible mechanism was proposed on the basis of the experimental results. This work is complementary to the existing methods offering advantages, e.g., switchable diastereoselectivity using a readily synthesized chiral starting material, a cheap and readily available base catalyst, and a simple and practical operation, enabling synthetic application in organic synthesis.