Catalytic Reductive Coupling of Epoxides and Aldehydes: Epoxide Ring Opening Precedes Carbonyl Reduction

Angewandte Chemie 44(1), 129-132, DOI: 10.1002/anie.200461705

Several lines of evidence suggest that reduction of the carbonyl group occurs after epoxide-ring opening in the first examples of catalytic, reductive coupling of epoxides and aldehydes (see scheme). The hydroxyether products are obtained with >95:5 regioselectivity in all cases, independent of the steric and electronic nature of R1 and R2.