Direct Photocatalytic Synthesis of Medium-Sized Lactams by C-C Bond Cleavage.

Angew Chem Int Ed Engl

Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen, 518055, China.

Published: October 2018

Reported is a novel two-step ring-expansion strategy for expeditious synthesis of all ring sizes of synthetically challenging (hetero)aryl-fused medium-sized lactams from readily available 5-8-membered cyclic ketones. This step-economic approach features a remote radical (hetero)aryl migration from C to N under visible-light conditions. Broad substrate scope, good functional-group tolerance, high efficiency, and mild reaction conditions make this procedure very attractive. In addition, this method also provides expedient access to 13-15-membered macrolactams upon an additional one-step manipulation. Mechanistic studies indicate that the reaction involves an amidyl radical and is promoted by acid.

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http://dx.doi.org/10.1002/anie.201808890DOI Listing

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