Highly Selective Coupling ofAlkenes and Aldehydes Catalyzed by NHC-Ni-P(OPh)3: Synergy Between a Strong σ-Donor and a Strong π-Acceptor

Angewandte Chemie 46(5), 782-785, DOI: 10.1002/anie.200603907

Give and take: Both a strong electron donor (1) and a strong electron acceptor (P(OPh)3) are necessary for a highly selective, nickel-catalyzed coupling reaction between alkenes, aldehydes, and silyl triflates (see scheme; cod=cycloocta-1,5-diene, Tf=trifluoromethanesulfonyl). This synergistic effect may also be useful in other transformations catalyzed by NHC–metal complexes (NHC=N-heterocyclic carbene).