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Updated: Jun 29, 2026

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Regiochemistry in aryl radical cyclization onto methylenecycloalkanes
Ishibashi1, Kobayashi, Nakashima
1Faculty of Pharmaceutical Sciences, Kanazawa University, Takara-machi, Kanazawa 920-0934, Japan.
Abstract:
Bu(3)SnH-mediated aryl radical cyclization onto methylenecycloalkanes having a phenylthio, an ester, or a nitrile group at the terminus of the alkenic bond provides exclusively exo cyclization products. The results are in sharp contrast to those reported for nonsubstituted methylenecycloalkanes, which give exclusively endo cyclization products. Formation of endo cyclization products has been suggested to be a result of a consecutive 5-exo cyclization of an aryl radical and neophyl rearrangement. The exo-selective aryl radical cyclization offers a new method for synthesizing fused aromatic compounds containing a benzylic quaternary carbon atom.
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