ZrCl4 catalyzed highly selective and efficient Michael addition of heterocyclic enamines with α,β-unsaturated olefins

Highly selective and efficient Michael additions of heterocyclic enamines, viz. indoles, pyrroles, and pyrazoles with alpha, beta-unsaturated olefins using 2 mol % of ZrC14 has been achieved. (c) 2006 Elsevier Ltd. All rights reserved.