Electrochemical Proton Reduction over Nickel Foam for Z-Stereoselective Semihydrogenation/deuteration of Functionalized Alkynes

Selective reduction strategies based on abundant-metal catalysts are very important in the production of chemicals. In this paper, a method for the electrochemical semihydrogenation and semideuteration of alkynes to form Z-alkenes was developed, using a simple nickel foam as catalyst and H3O+ or D3O+ as sources of hydrogen or deuterium. Good yields and excellent stereoselectivities (Z/E up to 20: 1) were obtained under very mild reaction conditions. The reaction proceeded with terminal and nonterminal alkynes, and also with alkynes containing easily reducible functional groups, such as carbonyl groups, as well as aryl chlorides, bromides, and even iodides. The nickelfoam electrocatalyst could be recycled up to 14 times without any change in its catalytic properties.

Automated summary

This paper presents a method for the electrochemical semihydrogenation and semideuteration of alkynes to form Z-alkenes using nickel foam as a catalyst. The reaction demonstrated good yields and excellent stereoselectivities under mild conditions, showing versatility in substrates. The recyclability of the nickel foam electrocatalyst was up to 14 cycles without loss of catalytic properties.