Asymmetric Synthesis of Spirobenzazepinones with Atroposelectivity and Spiro-1,2-Diazepinones by NHC-Catalyzed [3+4] Annulation Reactions
作者:Lei Wang、Sun Li、Marcus Blümel、Arne R. Philipps、Ai Wang、Rakesh Puttreddy、Kari Rissanen、Dieter Enders
DOI:10.1002/anie.201604819
日期:2016.9.5
A strategy for the NHC‐catalyzed asymmetric synthesis of spirobenzazepinones, spiro‐1,2‐diazepinones, and spiro‐1,2‐oxazepinones has been developed via [3+4]‐cycloaddition reactions of isatin‐derived enals (3C component) with in‐situ‐generated aza‐o‐quinonemethides, azoalkenes, and nitrosoalkenes (4atom components). The [3+4] annulation strategy leads to the seven‐membered target spiro heterocycles
Aerobic Oxidative Cycloaddition of α-Chlorotosylhydrazones with Arylamines: General Chemoselective Construction of 1,4-Disubstituted and 1,5-Disubstituted 1,2,3-Triazoles under Metal-Free and Azide-Free Conditions
作者:Hui-Wen Bai、Zhong-Jian Cai、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1021/acs.orglett.5b01000
日期:2015.6.19
A novel synthetic approach toward 1,4-disubstituted 1,2,3-triazoles and 1,5-disubstituted 1,2,3-triazoles by aerobic oxidative cycloaddition of alpha-chlorotosylhydrazone with primary aryl amine has been developed. Significantly, the reaction proceeds smoothly to afford 1,4-disubstituted 1,2,3-triazoles and 1,5-disubstituted 1,2,3-triazoles under catalyst-free, metal-free, azide-free, and peroxide-free conditions.