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.
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。
Reactions of Sulfonylphthalide with Diverse Activated Imines for the Synthesis of Enaminophthalides, <i>Spiro</i>-isoquinolinones, and Homalicine Natural Products
作者:Pallabita Basu、Nishikant Satam、Soumyaranjan Pati、Alati Suresh、Irishi N. N. Namboothiri
DOI:10.1021/acs.joc.2c00816
日期:——
various activated imines under basic conditions is demonstrated. The reaction of 3-sulfonylphthalide with Boc-protected aldimine provides a rapid access to 1,2-imine adducts and alkylidenephthalides depending upon the stoichiometry of the base. The alkylidenephthalides could be transformed to ketophthalides, a new class of phthalides, on acid hydrolysis, which upon reductive cyclization using Zn/AcOH
When 2-ethynylbenzoic acids were treated with a catalytic amount of a rhenium complex, such as ReCl(CO())5, 6-endo cyclization of 2-ethynylbenzoic acids proceeded with a high selectivity to give the corresponding isocoumarins in moderate to good yields.
Oxidation of 3-arylisochromans by dimethyldioxirane. An easy route to substituted 3-arylisocoumarins
The selective oxidation of the two different benzylethereal position of 3-arylisochromans by dimethyldioxirane as a function of different substituents on the aromatic rings was studied. The easy oxidation of these compounds was exploited for a new easy access to substituted 3-arylisocoumarins. (C) 1999 Elsevier Science Ltd. All rights reserved.