Enable biomass-derived alcohols mediated alkylation and transfer hydrogenation

A single-atom catalyst with generally regarded inert Zn–N4 motifs derived from ZIF-8 is unexpectedly efficient for the activation of alcohols, enabling alcohol-mediated alkylation and transfer hydrogenation. C-alkylation of nitriles, ketones, alcohols, N-heterocycles, amides, keto acids, and esters, and N-alkylation of amines and amides all go smoothly with the developed method. Taking the α-alkylation of nitriles with alcohols as an example, the α-alkylation starts from the (1) nitrogen-doped carbon support catalyzed dehydrogenation of alcohols into aldehydes, which further condensed with nitriles to give vinyl nitriles, followed by (2) transfer hydrogenation of C=C bonds in vinyl nitriles on Zn–N4 sites. The experimental results and DFT calculations reveal that the Lewis acidic Zn-N4 sites promote step (2) by activating the alcohols. This is the first example of highly efficient single-atom catalysts for various organic transformations with biomass-derived alcohols as the alkylating reagents and hydrogen donors. Using carbonyl compounds or alcohols as alkylating reagents for the synthesis of α-alkylated nitriles is appealing from a sustainability perspective. Here, a single-atom catalyst with Zn–N4 motifs acting as Lewis acid sites effectively activates alcohols, thus promoting various alkylation and transfer hydrogenation reactions using biomass-derived alcohols as both the alkylating reagents and hydrogen donors.