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Photoredox-Catalyzed Cyclobutane Synthesis by a Deboronative Radical Addition-Polar Cyclization Cascade.

ABSTRACT: Photoredox-catalyzed methylcyclobutanations of alkylboronic esters are described. The reactions proceed through single-electron transfer induced deboronative radical addition to an electron-deficient alkene followed by single-electron reduction and polar 4-exo-tet cyclization with a pendant alkyl halide. Key to the success of the methodology was the use of easily oxidizable arylboronate complexes. Structurally diverse cyclobutanes are shown to be conveniently prepared from readily available alkylboronic esters and a range of haloalkyl alkenes. The mild reactions display excellent functional group tolerance, and the radical addition-polar cyclization cascade also enables the synthesis of 3-, 5-, 6-, and 7-membered rings.

SUBMITTER: Shu C

PROVIDER: S-EPMC6492184 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Photoredox-Catalyzed Cyclobutane Synthesis by a Deboronative Radical Addition-Polar Cyclization Cascade.

Shu Chao C Noble Adam A Aggarwal Varinder K VK

Angewandte Chemie (International ed. in English) 20190215 12

Photoredox-catalyzed methylcyclobutanations of alkylboronic esters are described. The reactions proceed through single-electron transfer induced deboronative radical addition to an electron-deficient alkene followed by single-electron reduction and polar 4-exo-tet cyclization with a pendant alkyl halide. Key to the success of the methodology was the use of easily oxidizable arylboronate complexes. Structurally diverse cyclobutanes are shown to be conveniently prepared from readily available alky ...[more]

PMID: 30681266

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