Highly Active Rhodium-Diene Complexes for [4+2] Cycloadditions

Significance The Rh-catalyzed [4+2] cycloaddition yields enantiomerically enriched annulated ring systems which can be valuable intermediates in synthesis. The authors found that rhodium-diene complexes give highly active catalysts and compare favorably to the previously reported diphosphine-rhodium complexes (Related work: K. Mikami and co-workers J. Am. Chem. Soc. 2006 , 128 , 12648).