Synfacts 2009(6): 0632-0632  
DOI: 10.1055/s-0029-1216713
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart ˙ New York

Rhodium-Catalyzed [2+2+2] Cycloaddition of Alkynes and Alkenyl Isocyanates

Contributor(s): Hisashi Yamamoto, Pingfan Li
R. T. Yu, E. E. Lee, G. Malik, T. Rovis*
Colorado State University, Fort Collins, USA
Further Information

Publication History

Publication Date:
25 May 2009 (online)

Significance

This report presents the rhodium-­catalyzed [2+2+2] cycloaddition of alkyl alkynes and alkenyl isocyanates to generate indolizidine structures in good yields and high enantioselectivities. The choice of ligand can switch the product preference from previously reported bicyclolactams to the desired indolizidines, and it is believed to be resulting from the regioselective formation of metalacycle I over IV, and subsequent CO migrations (I to II to III).