Carbon-carbon bond formation in regio- and stereoselective palladium-catalyzed cyclization of allene-substituted conjugated dienes

J Löfstedt; J Franzén; J E Bäckvall

doi:10.1021/jo0157324

Carbon-carbon bond formation in regio- and stereoselective palladium-catalyzed cyclization of allene-substituted conjugated dienes

J Org Chem. 2001 Nov 30;66(24):8015-25. doi: 10.1021/jo0157324.

Authors

J Löfstedt¹, J Franzén, J E Bäckvall

Affiliation

¹ Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.

PMID: 11722199
DOI: 10.1021/jo0157324

Abstract

Regio- and stereoselective palladium-catalyzed reactions of allene-substituted 1,3-dienes 1 in acetic acid at room temperature lead to cyclization with formation of a carbon-carbon bond between the middle carbon of the allene and the terminal carbon of the 1,3-diene. Two different types of reactions, both that constitute 1,4-carboacetoxylations of the 1,3-diene, have been developed. In one of the reactions, Pd(II) catalyzes the oxidation of 1 to bicyclic compounds 2, and in the other, Pd(0) catalyzes the transformation of 1 to bicyclic compounds 3. The products 2 are useful for further synthetic transformations and undergo Diels-Alder reactions with dienophiles to give polycyclic ring systems.