Nickel/photoredox-catalyzed boryl radical relay dual arylation/acylation of alkenes

Abstract

Herein, we report a novel dual nickel/photoredox catalytic system for alkene diarylation and diacylation, centered around a unique boron-mediated radical relay mechanism. The key steps of this process involve the efficient cleavage of B–H bonds and the selective activation of inert C(sp²)–X bonds. Specifically, photocatalytically generated bromine radicals first undergo hydrogen atom transfer (HAT) with amine-boranes, cleaving the B–H bond. The resulting boryl radicals then serve as potent activators to engage inert aryl bromides or acyl chlorides via halogen atom transfer (XAT), effectively breaking the C(sp²)–X bonds and releasing key aryl and acyl radicals. These carbon-centered radicals subsequently add to alkenes, and the resulting adducts are efficiently captured by nickel species and funneled into a downstream nickel catalytic cycle to accomplish alkene difunctionalization. This strategy is distinguished by its broad substrate compatibility, excellent chemo-selectivity, capability for late-stage functionalization of drug molecules, and the use of commercially available and stable reagents. It thus provides an efficient and reliable route to synthetically valuable 1,2-diaryl- and 1,2-diacyl-substituted compounds.