Synfacts 2007(1): 0069-0069  
DOI: 10.1055/s-2006-955725
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Chiral Quaternary Carbon Stereocenters via Diene-yne [2+2+2] Cycloaddition

Contributor(s): Mark Lautens, Andrew Martins
T. Shibata*, Y-k. Tahara
Waseda University, Tokyo, Japan
Further Information

Publication History

Publication Date:
15 December 2006 (online)

Significance

In the presence of a [Rh(cod)2]BF4/Tol-BINAP catalyst system, diene-ynes can be converted into either chiral substituted norbor­nenes or chiral bicyclic dienes in one step with excellent enantioselectivity and good to excellent yield. The key to the divergent product selectivity is the diene substitutent R3, which is proposed to control the mechanism of the final bond-forming step. The reaction was also performed under an acetylene atmosphere, forming an allyl diene product in low yield.