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Visible light-induced halogen-atom transfer by N-heterocyclic carbene-ligated boryl radicals for diastereoselective C(sp³)-C(sp²) bond formation.

ABSTRACT: Photoinduced halogen-atom transfer (XAT) has rapidly emerged as a programmable approach to generate carbon-centered radical intermediates, mainly relying on silyl and α-aminoalkyl radicals as halogen abstractors. More recently, ligated boryl radicals have also been proposed as effective halogen abstractors under visible-light irradiation. In this study, we describe the use of this approach to enable C(sp³)-C(sp²) bond formation via radical addition of carbon-centered radicals generated via XAT onto chloroalkynes. Our mechanistic investigation reveals a complex interplay of highly reactive radical intermediates which, under optimized conditions, delivered the targeted vinyl chlorides in excellent yields and Z : E ratios. Finally, we demonstrated the synthetic value of these products in transition metal-based cross-coupling reactions.

SUBMITTER: Capaldo L

PROVIDER: S-EPMC11340342 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature

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Visible light-induced halogen-atom transfer by N-heterocyclic carbene-ligated boryl radicals for diastereoselective C(sp3)-C(sp2) bond formation.

Capaldo Luca L Wan Ting T Mulder Robin R Djossou Jonas J Noël Timothy T

Chemical science 20240813

Photoinduced halogen-atom transfer (XAT) has rapidly emerged as a programmable approach to generate carbon-centered radical intermediates, mainly relying on silyl and α-aminoalkyl radicals as halogen abstractors. More recently, ligated boryl radicals have also been proposed as effective halogen abstractors under visible-light irradiation. In this study, we describe the use of this approach to enable C(sp3)-C(sp2) bond formation via radical addition of carbon-centered ...[more]

PMID: 39184300

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