Formation of Fused Aromatic Architectures via an Oxidative Dearomatization - Radical Cyclization Rearomatization Approach.

A new mild C-C bond forming cyclization approach of catechol derivatives is reported. This approach relies on an initial dearomatization step using lead (IV) acetate followed by a carefully controlled radical cyclization step, which under the reaction conditions also facilitates rearomatization. Triethylborane is the key to the success of this reaction as it enables the reaction to proceed at low temperatures and is also believed to aid rearomatization. The amount and ratio of triethylborane and reducing agent (tributyltinhydride) that is employed as well as the concentration the reaction is run at are all essential to the success of this new approach.