Electrochemical dehydrogenative cyclization of 1,3-dicarbonyl compounds
作者:Zheng-Jian Wu、Shi-Rui Li、Hao Long、Hai-Chao Xu
DOI:10.1039/c8cc02472c
日期:——
The intramolecular C(sp3)–H/C(sp2)–H cross-coupling of 1,3-dicarbonyl compounds has been achieved through Cp2Fe-catalyzed electrochemical oxidation. The key to the success of these dehydrogenative cyclization reactions is the selective activation of the acidic α-C–H bond of the 1,3-dicarbonyl moiety to generate a carbon-centered radical.
The series of 3-monofunctionalized 2-oxindoles 2 were conveniently synthesized from reactions between anilide 1 and phenyliodine(III) diacetate (PIDA) through hypervalent iodine mediated C(sp(2))-C(sp(2)) bond formation followed by a subsequent deacylation reaction. This metal-free method, shown to provide direct access to an important oxindole intermediate, could be applied to the total synthesis of naturally occurring horsfiline.
Effects of catalysts on the cyclization of 2-diazo-2-methoxycarbonyl-N-aryl-N-alkylethanamides
作者:Keith Smith、Dawoud Bahzad
DOI:10.1039/p19960002793
日期:——
Inorganic solids have pronounced effects on the product distribution from decomposition of the title compounds; zeolite Kβ is particularly useful for directing the synthesis of indolinones such as 5-methoxy-N-methylindolin-2-one, which is formed in 89% yield from 2-diazo-2-methoxycarbonyl-N-(4-methoxyphenyl)-N-methylethanamide; speculation is made about a possible mechanism.
Synthesis of C3-Fluorinated Oxindoles through Reagent-Free Cross-Dehydrogenative Coupling
作者:Zheng-Jian Wu、Hai-Chao Xu
DOI:10.1002/anie.201701329
日期:2017.4.18
herein is an unprecedented synthesis of C3‐fluorinated oxindoles through cross‐dehydrogenative coupling of C(sp3)‐H and C(sp2)‐H bonds from malonate amides. Under the unique and mild electrochemical conditions, the requisite oxidant and base are generated in a continuous fashion, allowing the formation of the base‐ and heat‐sensitive 3‐fluorooxindoles in high efficiency with broad substrate scope. The synthetic