Rh-precatalyst leads to a switch in regioselectivity
a Reaction conditions: 1a (0.1 mmol), 2d (0.5 mmol), [Rh] (5 mol%), ligand (5 mol%), DCE (0.2 mL), 15 h. Isolated yield. Regioselectivity ratio (rr) is the ratio of f 3ad to 6ad, which is determined by 1H NMR analysis of reaction mixture. b Using dppe as ligand, 3 h.