Asymmetric Michael addition of formaldehyde N,N-dialkylhydrazones to alkylidene malonates
Abstract
Enantiopure formaldehyde N,N-dialkylhydrazones 1 smoothly react with prochiral alkylidene malonates 2 in the presence of MgI2 to afford the corresponding Michael adducts 3 in excellent yields and good diastereoselectivities; direct racemization-free BF3·OEt2-catalyzed thiolysis of the N bond affords the corresponding