Highly efficient stereoselective catalytic C(sp ³)-H insertions with donor rhodium carbenoids generated from cyclopropenes

Rings of five and six: Donor alkenyl rhodium carbenoids generated from 3,3-dimethylcyclopropenylcarbinols exhibit high reactivity in intramolecular C-H insertions. The reactions proceed under remarkably mild conditions, tolerate the presence of the free hydroxy group, and afford an efficient and stereoselective access to a variety of functionalized carbocycles and oxygen heterocycles.