Highly Diastereoselective Crown Ether Catalyzed Arylogous Michael Reaction of 3-Aryl Phthalides
作者:Marina Sicignano、Antonella Dentoni Litta、Rosaria Schettini、Francesco De Riccardis、Giovanni Pierri、Consiglia Tedesco、Irene Izzo、Giorgio Della Sala
DOI:10.1021/acs.orglett.7b02113
日期:2017.8.18
The first arylogous Michael reaction of 3-aryl phthalides has been developed. The reaction, promoted by catalytic amounts of KOH or K3PO4 and dibenzo-18-crown-6, affords the corresponding 3,3-disubstituted phthalides in good to high yields and as single diastereomers in nearly all studied cases.
已经开发了第一个3-芳基邻苯二甲酸酯的迈克尔反应。由催化量的KOH或K 3 PO 4和二苯并18-冠-6促进的反应,以几乎所有的研究情况,均以高收率和高收率提供了相应的3,3-二取代邻苯二甲酸酯。
Scalable Electrochemical Dehydrogenative Lactonization of C(sp<sup>2</sup>/sp<sup>3</sup>)–H Bonds
A practical, electrochemical method is developed for the direct dehydrogenative lactonization of C(sp2/sp3)–H bonds under external oxidant- and metal-free conditions, delivering diverse lactones, including coumarin derivatives with excellent regioselectivity. The scalable nature of this newly developed electrochemical process was demonstrated on a 40 g scale following an operationally simple protocol
Synthesis of synthons: The asymmetric hydrogenation and subsequent in situ lactonization with Ru-diphosphines results in the direct conversion of a series of 2-acylarylcarboxylates including 2-aroylarylcarboxylates into the corresponding optically active 3-substituted phthalides under mild reaction conditions.
In a palladium-catalyzed oxidative esterification, hydrosilane can serve as an activator of palladium catalyst with bismuth, thus leading to a novel ligand- and silver-free palladium catalyst system for facile oxidative esterification of a variety of benzylic alcohols in good yields.
Rhenium-Catalyzed Phthalide Synthesis from Benzamides and Aldehydes via C–H Bond Activation
作者:Bing Jia、Yunhui Yang、Xiqing Jin、Guoliang Mao、Congyang Wang
DOI:10.1021/acs.orglett.9b02142
日期:2019.8.16
The [4 + 1] annulation of benzamides and aldehydes for phthalide synthesis was achieved via rhenium-catalyzed C–H activation, which demonstrates an unprecedented reaction pattern distinct from those of other transition-metal catalyses. The reaction also features readily available starting materials, a wide scope for both electro-rich and electro-deficient substrates, and the elimination of homoannulation