Heterodimerization of Propylene and Vinylarenes: Functional Group Compatibility in a Highly Efficient Ni-Catalyzed Carbon–Carbon Bond-Forming Reaction

Unlike heterodimerization reactions of ethylene and vinylarenes, no such synthetically useful reactions using propylene are known. We find that propylene reacts with various vinylarenes in the presence of catalytic amounts of [(allyl)NiBr]2, triphenylphosphine and AgOTf giving excellent yields of the dimerization products. The reaction proceeds at 1 atm of propylene at temperatures between −15 and 10°C. These conditions are compatible with a number of common organic functional groups such as halides, ethers, esters, ketones and sulfonamides. As expected, a mixture of regioisomeric products (with propene-C1 addition to the benzylic position as the major one) is obtained. The product distribution appears to be significantly different when a hemilabile ligand (2-diphenylphosphino-2′-alkoxy-1,1′-binaphthyl) is employed.