Key Laboratory of Drug-Targeting and Drug Delivery System of the Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, China.
College of Pharmacy, Third Military Medical University, Chongqing, 400038, China.
Angew Chem Int Ed Engl. 2019 Mar 18;58(12):4036-4040. doi: 10.1002/anie.201814403. Epub 2019 Feb 14.
Auto-tandem catalysis (ATC), in which a single catalyst promotes two or more mechanistically different reactions in a cascade pattern, provides a powerful strategy to prepare complex products from simple starting materials. Reported here is an unprecedented auto-tandem cooperative catalysis (ATCC) for Morita-Baylis-Hillman carbonates from isatins and allylic carbonates using a simple Pd(PPh ) precursor. Dissociated phosphine generates phosphorus ylides and the Pd leads to π-allylpalladium complexes, and they undergo a γ-regioselective allylic-allylic alkylation reaction. Importantly, a cascade intramolecular Heck-type coupling proceeds to finally furnish spirooxindoles incorporating a 4-methylene-2-cyclopentene motif. Experimental results indicate that both Pd and phosphine play crucial roles in the catalytic Heck reaction. In addition, the asymmetric versions with either a chiral phosphine or chiral auxiliary are explored, and moderate results are obtained.
自动串联催化（ATC），其中单个催化剂以级联模式促进两个或更多具有不同机理的反应，为从简单起始原料制备复杂产物提供了强大的策略。本文报道了一种前所未有的使用简单的 Pd(PPh 3 ) 前体从色酮和烯丙基碳酸酯制备 Morita-Baylis-Hillman 碳酸酯的自动串联协同催化（ATCC）。解离的膦生成磷叶立德，钯导致π-烯丙基钯配合物，它们经历γ-区域选择性烯丙基-烯丙基烷基化反应。重要的是，级联的分子内 Heck 型偶联反应最终生成了含有 4-亚甲基-2-环戊烯基的螺环氧化吲哚。实验结果表明，钯和膦在催化 Heck 反应中都起着至关重要的作用。此外，还探索了具有手性膦或手性助剂的不对称版本，得到了中等的结果。
