Sahu T.K.; Vishwakarma A.; Kumar V.; Khan R.; Khan T.2025-02-1720242http://dx.doi.org/10.1002/ajoc.202400022https://idr.iitbbs.ac.in/handle/2008/5109Convenient access to 6-alkylsulfonylmethyl phenanthridines has been demonstrated both under non-catalytic thermal and visible-light photoredox-catalyzed conditions. A cascade of radical cyclization is triggered by the exposure of biphenyl vinyl azides to the in-situ generated alkyl sulfonyl radicals from 4-substituted Hanztsch esters in the presence of an SO2 surrogate. Transition metal-free, mild reaction conditions, and broad substrate scope constitute some of the highlights of the approach. Also, the synthetic utility of the accessed 6-alkylsulfonylmethyl phenanthridines has been demonstrated. � 2024 Wiley-VCH GmbH.enCyclization; Nitrogen heterocycles; Photocatalysis; Radical reactions; SO₂-fixationArticle