NHC-catalyzed annulation of enals and chalcones: further explorations on the novel synthesis of 1,3,4-trisubstituted cyclopentenes
摘要:
The facile synthesis of 1,3,4-trisubstituted cyclopentenes via homoenolate annulation of enals with heterocycle substituted chalcones is described. (C) 2011 Elsevier Ltd. All rights reserved.
Cooperative <i>N</i>-Heterocyclic Carbene/Lewis Acid Catalysis for Highly Stereoselective Annulation Reactions with Homoenolates
作者:Benoit Cardinal-David、Dustin E. A. Raup、Karl A. Scheidt
DOI:10.1021/ja910666n
日期:2010.4.21
A new approach that takes advantage of N-heterocyclic carbene/Lewis acidcooperativecatalysis provides access to cis-1,3,4-trisubstituted cyclopentenes from enals and chalcone derivatives with high levels of diastereoselectivity and enantioselectivity. The presence of Ti(OiPr)(4) as the Lewis acid allows for efficient substrate preorganization, which translates into high levels of diastereoselectivity