BpCu-Catalyzed Cyclopropanation of Olefins: A Simple System That Operates under Homogeneous and Heterogeneous Conditions (Bp = Dihydridobis(pyrazolyl)borate)†

The complexes BpCu (1), BpCuL (L = bipy, 2; L = Ph2PCH2CH2PPh2, 3; L = PCy3, 4) and BpCuL2 (L = py, 5; L = PPh3, 6) catalyze the cyclopropanation of olefins in moderate to high yields in the homoge...