Bhaskar Pal Kumar, Di Tommaso Ester Maria, Inge A Ken, Olofsson Berit
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden.
Department of Materials and Environmental Chemistry, Stockholm University, 10691, Stockholm, Sweden.
Angew Chem Int Ed Engl. 2023 May 8;62(20):e202301368. doi: 10.1002/anie.202301368. Epub 2023 Apr 12.
We report an efficient radical-mediated C-C coupling through photoredox-catalyzed reactions of 4-alkyl-dihydropyridines (DHPs) and vinylbenziodoxol(on)es (VBX, VBO). This transition-metal-free and mild photocatalytic method has excellent functional group tolerance and affords vinylated products in good yields, with complete retention of the alkene configuration. The utility of the methodology is demonstrated by the diastereoselective synthesis of C-vinyl glycosides. Preliminary mechanistic studies suggest that the C-C bond formation is stereospecific and proceeds through a concerted radical coupling transition state.
我们报道了一种通过光氧化还原催化的4-烷基二氢吡啶（DHP）与乙烯基苯碘酰（酮）（VBX、VBO）反应实现的高效自由基介导的碳-碳偶联。这种无过渡金属且温和的光催化方法具有出色的官能团耐受性，能以良好的产率得到乙烯基化产物，同时烯烃构型完全保留。该方法的实用性通过C-乙烯基糖苷的非对映选择性合成得以证明。初步机理研究表明，碳-碳键的形成具有立体专一性，且通过协同自由基偶联过渡态进行。
