Electrocatalytic Hydrogen Evolution Reaction Enabling Cyanation of Electron‐poor Carbons with Acetone Cyanohydrin

• Published in: European journal of organic chemistry 2024-06, Vol.27 (22), p.n/a
• Main Authors: Morlacci, Valerio, Momoli, Caterina, Ndrita, Meklind, Aschi, Massimiliano, Arcadi, Antonio, Palombi, Laura
• Format: Article
• Language: English
• Subjects: Acetone; acetone cyanohydrin; catalytic current; Cyano groups; Electricity consumption; electrochemical cyanation; Electrolysis; Hydrogen evolution reactions; Imines; Ketones; α-aminonitriles; β-cyanoketones
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.202400236

The Pt‐cathode hydrogen evolution reaction (Pt‐HER) of acetone cyanohydrin provides an alternative method for introducing the cyano group onto electrophilic carbons of imines and chalcones. The synthesis of α‐aminonitriles and β‐cyano ketones has been achieved smoothly with a small excess of cyanating agent (2 equivalent), catalytic amount of supporting electrolyte and low electricity consumption (0.02 F/mol). Besides demonstrating a general atom economy, the high Faradaic efficiency, allows for a scale‐up with low‐demanding electrochemical design and short electrolysis times. Herein is reported an electrochemical procedure based on the Hydrogen Evolution Reaction of acetone cyanohydrin at a Pt cathode enabling the cyanation of α,β‐ unsaturated carbonyl and imines. Catalytic current, along with a correspondingly reduced quantity of supporting electrolyte, facilitates the scalability of the procedure, ensuring brief electrolysis times while maintaining a simple electrochemical design.