Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany.
The Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100199, China.
Angew Chem Int Ed Engl. 2017 Jul 10;56(29):8516-8521. doi: 10.1002/anie.201704210. Epub 2017 Jun 20.
A novel NHC-catalyzed annulation protocol for the asymmetric synthesis of biologically important β-lactam fused spirocyclopentane oxindoles with four contiguous stereocenters, including two quaternary carbon centers, was developed. Alternatively, spirocyclopentane oxindoles containing an enaminone moiety can be achieved using the same starting materials, isatin-derived enals, and N-sulfonyl ketimines, in the presence of a slightly different NHC catalytic system. This switchable annulation strategy enables the selective assembly of both heterocyclic scaffolds with good yields and excellent enantioselectivities for a broad range of substrates.
一种新型的 NHC 催化的环化反应协议，用于不对称合成具有四个连续立体中心的生物重要的β-内酰胺稠合螺环戊烷氧吲哚，包括两个季碳中心。或者，使用相同的起始原料、色酮衍生的烯醛和 N-磺酰基亚胺，在略有不同的 NHC 催化体系的存在下，可以实现含有烯胺酮部分的螺环戊烷氧吲哚。这种可切换的环化策略能够选择性地组装两种杂环骨架，对于广泛的底物，具有良好的产率和优异的对映选择性。
