for the preparation of 3-substituted isocoumarins via palladium-catalyzed nucleophilic addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective nucleophilic addition and C–H functionalization procedure.
The Rh(III)-catalyzed C–H activation initiated cyclization of benzoicacids with electron-rich geminal-substituted vinyl acetates was described. The reaction was employed to prepare a range of 3-aryl and 3-alkyl substituted isocoumarins selectively.
Sulfoxonium Ylides as Carbene Precursors: Rhodium(III)‐Catalyzed Sequential C−H Functionalization, Selective Enol Oxygen‐Atom Nucleophilic Addition, and Hydrolysis
作者:Yuanqiong Huang、Xueli Lyu、Hongjian Song、Qingmin Wang
DOI:10.1002/adsc.201900861
日期:2019.11.19
Herein, we report a protocol for Rh(III)‐catalyzed annulation reactions between oxazolines and sulfoxonium ylides via a sequence involving C−H activation, selective enol oxygen‐atom nucleophilic addition, and hydrolysis. This practical, operationally simple protocol has a wide substrate range, excellent regioselectivity, and moderate to good yields.
Ru(<scp>ii</scp>)-Catalyzed C–H bond activation/annulation of <i>N</i>-iminopyridinium ylides with sulfoxonium ylides
作者:Xiang Li、Danlu Li、Xiaofei Zhang
DOI:10.1039/d1ob02427b
日期:——
A Ru(II)-catalyzed C–H bond activation/annulation of N-iminopyridinium ylides with sulfoxoniumylides has been developed for the synthesis of diverse functionalized isocoumarin derivatives. This method features broad substrate scope, high functional group tolerance, simple operation and silver salt-free conditions. Furthermore, the synthetic utility of this method is demonstrated by the alkenylation
已经开发了一种 Ru( II ) 催化的N-亚氨基吡啶叶立德与锍叶立德的 C-H 键活化/环化,用于合成各种官能化的异香豆素衍生物。该方法具有底物范围广、官能团耐受性高、操作简单、无银盐条件等特点。此外,该方法的合成效用通过产物的烯基化和生物活性 thunberginol A 的有效合成得到证明。