Phosphine-catalyzed one-pot synthesis of cyclopentenes from electron-deficient allene, malononitrile and aromatic aldehydes

A three component reaction of aryl aldehydes and malononitrile with ethyl 2,3-butadienoate catalyzed by triphenylphosphine has been developed. The reaction furnishes highly functionalized cyclopentenes in moderate to good yields in a one-pot process. (c) 2005 Elsevier Ltd. All rights reserved.