Enantioselective synthesis of spirocyclic cyclopentenes: asymmetric [3+2] annulation of 2-arylideneindane-1,3-diones with MBH carbonates derivatives catalyzed by multifunctional thiourea-phosphines

The [3+2] annulation reactions of 2-arylideneindane-1,3-diones with Morita-Baylis-Hillman (MBH) carbonates proceeded smoothly in the presence of multifunctional thiourea-phosphines to produce the corresponding quaternary carbon centered spirocyclic cyclopentenes in moderate yields, with high diastereoselectivities and enantioselectivities under mild conditions. The plausible reaction has been also discussed on the basis of previous literature. (C) 2012 Elsevier Ltd. All rights reserved.