Rhodium-Catalyzed [2+2+2] Cycloaddition of Carbodiimides

Significance

The authors are the first to demonstrate the enantioselective [2+2+2] cycloaddition utilizing carbodiimides to give complex bicyclic systems. Previously reported by this group was a similar reaction employing isocyanates to give the derivatives of 2 (see scheme summary) as the major compound. The introduction of the bulky imido moiety allowed the synthesis of 1 as the major product.