Synfacts 2009(12): 1355-1355  
DOI: 10.1055/s-0029-1218313
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Bicyclic Azocine Rings via Rh-Catalyzed [4+2+2] Cycloaddition

Contributor(s): Hisashi Yamamoto, Cheol Hong Cheon
R. T. Yu, R. K. Friedman, T. Rovis*
Colorado State University, Fort Collins, USA
Further Information

Publication History

Publication Date:
20 November 2009 (online)

Significance

The authors have developed the first enantioselective rhodium-catalyzed [4+2+2] cycloaddition of terminal alkynes and dienyl isocyanates. The desired bicyclic azocine ring products were obtained in good to high yields and excellent enantioselectivities. Mechanistic studies suggested that the cycloaddition might proceed via oxidative cyclization between the diene and isocyanate following path b as shown above.