Electrocatalytic Synthesis of Aryl-Propargyl Alcohols from Arylacetylenes with N,N-Dimethylacetamide and Water.

Propargyl alcohols serve as important building blocks in pharmaceuticals and materials science, yet their traditional synthesis often involves hazardous reagents and produces significant waste. Herein, we present an electrochemical hydroxymethylation of arylacetylenes that enables the direct and efficient synthesis of aryl-propargyl alcohols under mild conditions. This protocol uniquely employs water as the oxygen source and the solvent (DMA or DMF) as the methylene donor, eliminating the need for external oxidants or additional carbon sources. The reaction proceeds smoothly in an undivided cell, tolerates a broad range of functional groups, and is readily scalable to gram quantities as well as adaptable to continuous flow processes. Mechanistic studies, including isotope labeling and DFT calculations, confirm the incorporation of both the hydroxyl and methylene units from water and solvent, respectively, via an anodic oxidation pathway. This approach provides a practical and efficient route for constructing aryl-propargyl alcohols using simple, readily available components in an electrochemical setting.