Nickel-Catalyzed Dehydrogenation–Condensation–Rehydrogenation (DCR) Approach toward the Synthesis of Branched Primary Alcohols

We demonstrated the first Ni-catalyzed dehydrogenation-condensation-rehydrogenation (DCR) approach for the cross-coupling of two primary alkyl alcohols to β-alkylated primary alcohols. A wide variety of primary alkyl, aryl, and heteroaryl alcohols efficiently coupled with aliphatic primary and secondary alkyl alcohols and released water as a green byproduct (44 entries and up to 96% yield). Straightforward synthesis to chromane and sequential one-pot coupling to C3-substituted quinolines was enabled by nickel catalysis. Initial mechanistic studies including deuterium labeling experiments establish the sequential DCR strategy.