Polarity Umpolung Strategy for the Radical Alkylation of Alkenes

Abstract

Free radical mediated alkylation of alkenes is a challenging and largely unmet goal. Disclosed here is a conceptually novel “polarity umpolung” strategy for radical alkylation of alkenes using a portfolio of easily accessed, difunctional alkylating reagents. This strategy is achieved by substituting inherently nucleophilic alkyl radicals with electrophilic sulfone‐bearing surrogates, thus inverting the usual mode of reactivity. Along with alkylation, either an heteroaryl or oximino group is concurrently incorporated into the alkenes by a consecutive docking and migration process, leading to valuable products. The reaction displays a broad functional‐group tolerance under mild reaction conditions. The protocol opens new vistas for the late‐stage modification of complex natural products and drug molecules containing alkene moieties.

Intermolecular Radical Fluoroalkylative Olefination of Unactivated Alkenes

“…Thus, developing different intermolecular alkenylating approaches applicable to general unactivated alkenes is of high synthetic value yet remains unmet. Prompted by our achievements in the upgraded FGM protocol, namely docking-migration, [36][37][38][39] aimed to fill the gap in the present confined alkene scope, we considered pursuing the intermolecular fluoroalkylative olefination of alkenes, which offers superior generality and practicality over the intramolecular pattern. Herein, we reveal the proof-of-principle studies (Scheme 1b), in which a portfolio of rationally designed sulfone-based dual-function reagents was synthesized and applied in the radical-mediated fluoroalkylative olefination of alkenes.…”

Arylsulfonylacetate as Bifunctional Reagent for Photoredox Catalytic Alkylarylation of Alkynes

“…Bifunctional reagent, which employs a linker to bind two individual components, have recently been used for the rapid difunctionalization of unsaturated carbon-carbon bond [25][26][27][28][29][30][31][32][33] . Several brilliantly designed molecules have demonstrated powerful capacity as surrogates for both radical donors and acceptors, enabling the efficient difunctionalization of alkenes by Zhu [34][35][36][37][38] , Stephenson [39][40][41] , Nevado 42 and Hong [43][44][45] . In stark contrast, the use of bifunctional reagents for the difunctionalization of alkynes remains unexplored.…”