Visible-Light-Induced Decarboxylative Cyclization/Hydrogenation Cascade Reaction to Access Phenanthridin-6-yl(aryl)methanol by an Electron Donor–Acceptor Complex

A novel and efficient visible-light-induced decarboxylative cyclization/hydrogenation cascade reaction of α-oxocarboxylic acids and 2-isocyanobiaryls has been developed. Without the need of any external photosensitizer, oxidant, and reductant, this method offers a mild and green approach for the synthesis of diverse alcohols in moderate to good yields. A mechanism indicated that an electron donor–acceptor complex-driven decarboxylation, radical addition/cyclization, and in situ photochemical reduction of ketones to alcohols could be involved in the reaction.

本研究开发了一种新颖高效的可见光诱导α-氧代羧酸与2-异氰基联芳烃的脱羧环化/加氢级联反应。该方法无需使用任何外部光敏剂、氧化剂与还原剂，可为多种醇类化合物的合成提供温和绿色的路径，产物收率可达中等至良好水平。机理研究表明，该反应可能涉及电子给体-受体复合物驱动的脱羧过程、自由基加成/环化过程，以及酮类化合物的原位光化学还原制醇过程。