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Radical cyclizations of cyclic ene sulfonamides occur with ?-elimination of sulfonyl radicals to form polycyclic imines.

ABSTRACT: Radical cyclizations of cyclic ene sulfonamides provide stable bicyclic and tricyclic aldimines and ketimines in good yields. Depending on the structure of the precursor, the cyclizations occur to provide fused and spirocyclic imines with five-, six-, and seven-membered rings. The initial radical cyclization produces an ?-sulfonamidoyl radical that undergoes elimination to form the imine and a phenylsulfonyl radical. In a related method, 3,4-dihydroquinolines can also be produced by radical translocation reactions of N-(2-iodophenylsulfonyl)tetrahydroiso-quinolines. In either case, very stable sulfonamides are cleaved to form imines (rather than amines) under mild reductive conditions.

SUBMITTER: Zhang H

PROVIDER: S-EPMC3868638 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

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Radical cyclizations of cyclic ene sulfonamides occur with β-elimination of sulfonyl radicals to form polycyclic imines.

Zhang Hanmo H Hay E Ben EB Geib Steven J SJ Curran Dennis P DP

Journal of the American Chemical Society 20131101 44

Radical cyclizations of cyclic ene sulfonamides provide stable bicyclic and tricyclic aldimines and ketimines in good yields. Depending on the structure of the precursor, the cyclizations occur to provide fused and spirocyclic imines with five-, six-, and seven-membered rings. The initial radical cyclization produces an α-sulfonamidoyl radical that undergoes elimination to form the imine and a phenylsulfonyl radical. In a related method, 3,4-dihydroquinolines can also be produced by radical tran ...[more]

PMID: 24111991

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