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Generation of α-Boryl Radicals by H^. Transfer and their Use in Cycloisomerizations.

ABSTRACT: Carbon-centered radicals can be stabilized by delocalization of their spin density into the vacant p orbital of a boron substituent. α-Vinyl boronates, in particular pinacol (Bpin) derivatives, are excellent hydrogen atom acceptors. Under H₂ , in the presence of a cobaloxime catalyst, they generate α-boryl radicals; these species can undergo 5-exo radical cyclizations if appropriate double bond acceptors are present, leading to densely functionalized heterocycles with tertiary substituents on Bpin. The reaction shows good functional group tolerance with wide scope, and the resulting boronate products can be converted into other useful functionalities.

SUBMITTER: Shi S

PROVIDER: S-EPMC8582025 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature

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Generation of α-Boryl Radicals by H. Transfer and their Use in Cycloisomerizations.

Shi Shicheng S Salahi Farbod F Vibbert Hunter B HB Rahman Maleeha M Snyder Scott A SA Norton Jack R JR

Angewandte Chemie (International ed. in English) 20210915 42

Carbon-centered radicals can be stabilized by delocalization of their spin density into the vacant p orbital of a boron substituent. α-Vinyl boronates, in particular pinacol (Bpin) derivatives, are excellent hydrogen atom acceptors. Under H2 , in the presence of a cobaloxime catalyst, they generate α-boryl radicals; these species can undergo 5-exo radical cyclizations if appropriate double bond acceptors are present, leading to densely functionalized heterocycles with tertiary substit ...[more]

PMID: 34405506

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