Functionalization and Hydrogenation of Carbon Chains Derived from CO

Selective reactions that combine H(2), CO and organic electrophiles (aldehyde, ketones, isocyanide) to form hydrogenated C(3) and C(4) carbon chains are reported. These reactions proceed by CO homologation mediated by [W(CO)(6)] and an aluminum(I) reductant, followed by functionalization and hydrogenation of the chain ends. A combination of kinetics (rates, KIEs) and DFT calculations has been used to gain insight into a key step which involves hydrogenation of a metallocarbene intermediate. These findings expand the extremely small scope of systems that combine H(2) and CO to make well‐defined products with complete control over chain length and functionality.