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
Organocatalytic Michael Addition of Malonates to Isatylidene-3-acetaldehydes: Application to the Total Synthesis of (−)-Debromoflustramine E
作者:Renrong Liu、Junliang Zhang
DOI:10.1002/chem.201300977
日期:2013.6.3
Flustering oxindoles: An enantioselective synthesis of 3,3′‐disubstituted oxindoles by conjugate addition of malonates to isatylidene‐3‐acetaldehydes in high yield and enantioselectivity is developed (see scheme). The synthetic utility of this reaction is demonstrated by the synthesis of three oxindole core structures and the asymmetric total synthesis of debromoflustramine E.