Organocatalytic enantioselective cascade Michael-alkylation reactions: synthesis of chiral cyclopropanes and investigation of unexpected organocatalyzed stereoselective ring opening of cyclopropanes

A new amine-catalyzed cascade Michael-alkylation process is described for generating highly functionaluzed chiral cyclopropanes in one-pot transformation. The analysis has shown that both the organocatalyst diphenylprolinol TMS ether and the base NaOA has played essential roles in the formation of the products.