Synthesis of Ester-Substituted Indolo[2,1-a]isoquinolines via Photocatalyzed Alkoxycarbonylation/Cyclization Reactions.

A direct alkoxycarbonylation/cyclization reaction is accomplished under visible light-induced photoredox catalysis. With this approach, a variety of ester-substituted indolo[2,1-a]isoquinolines are prepared in good to excellent yields. It is worth noting that this method not only can afford the synthesis of indolo[2,1-a]isoquinolines but also can provide an alternative route for generating complex target structures bearing carboxylic esters.