Tunable Mono- or 1,1-Double Heck-type Coupling Reaction of Unconjugated Amido-alkenes with Remote Benzylic C(sp3)-H of N-Fluorobenzamides

Abstract

This work described a tunable copper-catalyzed intermolecular oxidative functionalization reaction of unactivated alkenes directed by the remote benzylic free radical of the N-fluoroamides, and the corresponding monoalkylation and 1,1-bialkylation products of unactivated alkenes were obtained in good yields, respectively. These two reactions proceeded via a nitrogen-centered free radical generation of N-fluoroamide in the presence of copper salt, an intramolecular 1,5-hydrogen atom transfer, followed by the newly formed benzylic free radical addition across the alkenes, single-electron transfer, and β-hydride elimination multiple-steps sequential process, as represented a mono Heck-type coupling and a 1,1-double Heck-type coupling reaction of unactivated alkenes on the whole. These protocols showed good substrates scope and produced the polysubstituted alkenes, which could be further transformed to diverse structural molecules. Besides, the plausible reaction mechanism was proposed with the combination of density function theory calculation and control experiments.