Cooperative Chiral Lewis Base/Palladium‐Catalyzed Asymmetric Syntheses of Methylene‐Containing δ‐Lactams

Abstract

AbstractWe herein report a two‐step approach for the enantioselective synthesis of novel chiral δ‐lactams. By using a cooperative chiral ITU/achiral Pd‐catalyst system, this protocol proceeds via an asymmetric α‐allylation of activated aryl esters first, followed by an acid‐mediated lactam formation. A variety of differently substituted products could be obtained with usually high levels of enantioselectivities and in reasonable yields (16 examples, up to 98 : 2 er and 73 % yield over two steps). In addition, further utilizations of the products via transformations of the exocyclic double bond were successfully carried out as well.