Efficient Photocatalytic Carbonyl Alkylative Amination Enabled by Titanium-Dioxide-Mediated Decarboxylation

Herein, a heterogeneous carbonyl alkylative amination reaction that proceeds by photoredox catalysis has been developed. The use of nano titanium dioxide (TiO₂ , 25 nm) as photocatalyst allows efficient synthesis of diverse amines in good to excellent yields. Mechanistic studies reveal a single-electron-transfer mechanism involving the photoexcitation of TiO₂ to generate alkyl radicals from carboxylic acids decarboxylation. This protocol highlights the utility of using heterogeneous semiconductor photocatalysts to promote a practical and general synthesis of complex amines from readily available feedstocks.