Tandem enantioselective conjugate addition-Mannich reactions:: efficient multicomponent assembly of dialkylzincs, cyclic enones and chiral N-sulfinimines

A convenient access to enantiopure beta-amino ketones through a multicomponent reaction of dialkyl zinc reagents, cyclic enones and chiral N-tert-butanesulfinimines is disclosed. Four diastereoisomers can be selectively obtained by the appropriate choice of the chiral ligand (L or ent-L) and the chiral N-sulfinimine (R-S or S-S). The protocol is particularly efficient when enolisable N-sulfinimines are used. (C) 2008 Elsevier Ltd. All rights reserved.