Radical Heteroarylation of Alkenes and Alkanes via Heteroaryl ­Migration

Abstract

Heteroarenes are important units in organic chemistry and are ubiquitous in natural products, pharmaceuticals, and numerous artificial molecules. Despite great efforts devoted to accessing heteroarenes, the development of new methods to efficiently produce heteroarenes remains a long-term interest. Recently, the strategy of radical-mediated heteroaryl migration has supplied a robust toolkit for the synthesis of a diversity of heteroaryl-containing compounds. This Account summarizes our recent achievements in this field and provides insight into the incorporation of heteroarenes into organic skeletons.

Silylation and (Hetero)aryl/alkenylation of Unactivated Alkenes via Radical-Mediated Distal 1,4-Migration with Hydrosilanes under Organophotocatalysis

“…Organic photoredox catalysis is a green, mild, and highly efficient synthetic tool, which has been applied to the construction of carbon–carbon and carbon–heteroatom bonds . Even though some alkenes can undergo cascade distal arylation migration with radicals via organic photocatalysis, such as trifluoro radicals, sulfonyl/sulfinyl radicals, fluorine-containing radicals, arylphosphonyl/acyl radicals, etc., little attention has been paid to organic photoredox silyl-mediated aryl/alkenyl migration of unactivated alkenes. With our continuous efforts in photomediated construction of carbon–silicon bonds by the addition of silyl radicals to unsaturated chemical bonds with hydrosilanes, we envisioned that, under the right set of conditions, silyl-mediated (hetero)­aryl/alkenyl migration reactions could be processed after the addition of silyl radicals to unactivated alkenes bearing (hetero)­aryl/alkenyl amines, enabling the simultaneous incorporation of silyl and (hetero)­aryl/alkenyl groups to alkenes, which would be beyond the well-established synthesis of organosilicon compounds.…”

Radical-Mediated α-tert-Alkylation of Aldehydes by Consecutive 1,4- and 1,3-(Benzo)thiazolyl Migrations

“…The alkylation reaction is initiated through the formation of an electron donor–acceptor (EDA) complex involving the in situ generated enamine intermediate and the α-bromo sulfone reactant. The process unfolds via a novel series of 1,4- and 1,3-heteroaryl migration events (Scheme C) . This approach not only circumvents the challenges associated with traditional methods but also enriches the toolbox for aldehyde alkylation.…”

“…The process unfolds via a novel series of 1,4- and 1,3-heteroaryl migration events ( Scheme 1 C). 6 This approach not only circumvents the challenges associated with traditional methods but also enriches the toolbox for aldehyde alkylation.…”