Visible-light-mediated Oxidation of 1-Benzyl-3,4-dihydroisoquinolines with Dioxygen: Switchable Synthesis of 1-Benzoylisoquinolines and 1-Benzoy-3,4-dihydrolisoquinolines

A visible-light-mediated metal-free oxidation of 1-BnDHIQs to switchable preparation of BzIQs and BzDHIQs has been realized in which dioxygen as an oxidant. 6,7-Dialkoxy BzIQs and BzDHIQs were comprehensively synthesized in this protocol. This protocol provides a facile route for the efficient synthesis of isoquinoline alkaloids. Mechanistic investigation suggested that radical pathway and ionic pathway may exist simultaneously and intermediate A may be the key compound for the formation of the products.