Visible light-mediated synthesis of α-alkoxy/hydroxy diarylacetaldehydes from terminal alkynes

A visible light-mediated approach enabling the use of alcohols as nucleophiles in a one-step synthesis of alpha-alkoxy/hydroxy diarylacetaldehydes is reported. The method allows the construction of a highly functionalized quaternary center via oxidative coupling of alkynes with benzoquinone and alcohols at room temperature. The use of alcohols as a nucleophile is made possible by the prudent use of copper(i) cyanide as a catalyst to increase the electrophilicity of in situ generated p-quinone methides. This mild and simple protocol works without discrimination between aliphatic and aromatic alkynes as coupling partners.

Automated summary

This study presents a visible light-mediated approach for the one-step synthesis of alpha-alkoxy/hydroxy diarylacetaldehydes using alcohols as nucleophiles. The method involves the oxidative coupling of alkynes with benzoquinone and alcohols at room temperature, enabling the construction of a highly functionalized quaternary center. The use of copper(I) cyanide as a catalyst increases the electrophilicity of in situ generated p-quinone methides, allowing alcohols to act as nucleophiles. This mild and simple protocol shows no discrimination between aliphatic and aromatic alkynes as coupling partners.