College of Chemistry & Chemical Engineering, Jiangxi Normal University, Nanchang, 330022, China.
Key Laboratory of Chemical Biology of Jiangxi Province, China.
Angew Chem Int Ed Engl. 2018 Feb 19;57(8):2115-2119. doi: 10.1002/anie.201711603. Epub 2018 Feb 2.
The first enantioselective polyene cyclization initiated by a BINOL-derived chiral N-phosphoramide (NPA) catalyzed protonation of an imine is described. The ion-pair formed between the iminium ion and chiral counter anion of the NPA plays an important role for controlling the stereochemistry of the overall transformation. This strategy offers a highly efficient approach to fused tricyclic frameworks containing three contiguous stereocenters, which are widely found in natural products. In addition, the first catalytic asymmetric total synthesis of (-)-ferruginol was accomplished with an NPA catalyzed enantioselective polyene cyclization, as the key step for the construction of the tricyclic core, with excellent yield and enantioselectivity.
描述了首例由手性 BINOL 衍生的 N-膦酰胺（NPA）引发的对映选择性聚烯烃环化反应，该反应通过亚胺的质子化作用实现。在 NPA 的亚胺阳离子和手性抗衡阴离子之间形成的离子对对于控制整体转化的立体化学具有重要作用。该策略提供了一种高效的方法，可构建含有三个连续立体中心的稠合三环骨架，此类骨架广泛存在于天然产物中。此外，通过 NPA 催化的对映选择性聚烯烃环化反应，首次实现了（-）-ferruginol 的全催化不对称总合成，该反应是构建三环核心的关键步骤，具有优异的收率和对映选择性。
