Copper Hydride-Catalyzed Net Hydroformylation of Unactivated Terminal Olefins

We report a copper-catalyzed method for the highly regioselective formal hydroformylation via hydroacetalization of simple terminal alkenes. The robust protocol employs a commercially available diethoxy methyl ester proelectrophile activated by cocatalytic Zn(OTf)2 and was found to operate on a variety of functionalized olefin substrates to provide acetal products with exclusive linear regioselectivity. Density functional theory studies support that the key C-C bond forming event between the alkyl copper and the oxocarbenium ion intermediates takes place via a frontside electrophilic substitution (SE2) mechanism with retention of configuration of the reacting Cu-C bond.