Enantioselective Michael Reaction of α-Alkyl-β-keto Esters and Enones under Multifunctional Catalysis

An efficient approach for the enantioselective Michael additions of beta-alkyl-beta-keto esters to beta-substituted alpha,beta-unsaturated ketones has been developed. The Michael products could be obtained in good to excellent yields (75-98%) with excellent diastereoselectivities (up to >99:1 dr) and enantioselectivities (up to 96% ee) and could easily be transformed into a synthetically useful hexahydrophenanthrene structure under mild conditions in good yield.