Enantioselective organocatalyzed cascade reactions to highly functionalized quinolizidines

An organocatalyzed one-pot Michael addition-Pictet-Spengler sequence of beta-ketoamides and alpha,beta-unsaturated aldehydes was developed, which provided access to highly substituted indolo[2,3-alpha]quinolizidines and benzo[alpha]quinolizidines in moderate to good yields and good to excellent enantioselectivities. For aromatic alpha,beta-unsaturated aldehydes 1a-j products 10a-r containing a stable enol configuration were obtained. (C) 2011 Elsevier Ltd. All rights reserved.