Metal-free cross-dehydrogenative C–N coupling of azoles with xanthenes and related activated arylmethylenes
摘要:
A metal-free C(sp(3))-H/N-H cross-coupling of azoles with xanthenes and related activated arylmethylenes is presented. Both the use of azoles and the activation pattern of C(sp(3))-H sources are essential for this transformation. In the presence of 2.0 equiv of benzoyl peroxide (BPO), methylenes bearing a heteroatom-bridged bisaryl group reacted with various azolic N-H sources to afford C-N bond forming products in usually excellent or quantitative yields, and the diphenylmethane and methylenes coactivated by a phenyl group and an adjacent heteroatom are less reactive. Mechanistic investigations suggest that a radical/radical cross-coupling pathway might be involved.[GRAPHICS].
Bu<sub>4</sub>NI-Catalyzed α-Oxyacylation of Carbonyl Compounds with Toluene Derivatives
作者:Chengliang Li、Tao Jin、Xinglu Zhang、Chunju Li、Xueshun Jia、Jian Li
DOI:10.1021/acs.orglett.6b00749
日期:2016.4.15
A TBAI (tetrabutylammonium iodide)-catalyzed direct α-oxyacylation of carbonylcompounds from readily available toluene derivatives has been developed. The distinguished features of this metal-free protocol include the employment of simple starting material, a wide carbonylcompound scope, and mild reaction conditions.
TBAI-catalyzed oxidative coupling of β-ketoesters with carboxylic acid: synthesis of α-carboxylic-β-ketoesters
作者:Xiaoqing Li、Can Zhou、Xiangsheng Xu
DOI:10.3998/ark.5550190.0013.913
日期:——
TBAI-catalyzedoxidativecoupling of β-ketoesters with carboxylicacid using TBHP as oxidant has been established. This transformation provides a facile and direct strategy for the synthesis of α-carboxylic-β-ketoesters.
Electrochemically Induced Intermolecular Cross-Dehydrogenative C–O Coupling of β-Diketones and β-Ketoesters with Carboxylic Acids
作者:Oleg V. Bityukov、Olesya K. Matveeva、Vera A. Vil’、Vladimir A. Kokorekin、Gennady I. Nikishin、Alexander O. Terent’ev
DOI:10.1021/acs.joc.8b02791
日期:2019.2.1
The electrochemicallyinduced cross-dehydrogenative C–O coupling of β-diketones and β-ketoesters (C–H reagents) with carboxylic acids (O–H reagents) was developed. An important feature of this reaction lies in the selective formation of intermolecular C–O coupling products in high yields, up to 92%, using DMSO as a solvent with a broad substrate scope in an undivided cell equipped with carbon and platinum
Herein, a copper/TBHP catalyst system for the α-C–H acyloxylation of carbonyl compounds is developed using terminal alkynes as the acyloxy source. A variety of carbonyl compounds and terminal alkynes are tolerated in this reaction. In addition, its possible mechanism is proposed.
One-pot synthesis of α-acyloxycarbonyl compounds via oxidative decarboxylation coupling reaction of α-oxo carboxylic acids with carbonyl compounds
作者:Li-Ming Chang、Gao-Qing Yuan
DOI:10.1016/j.tet.2016.09.031
日期:2016.11
With tetrabutylammonium iodide (TBAI) as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant, a simple metal-free protocol has been developed for the synthesis of α-acyloxycarbonyl compounds from carbonylcompounds and α-oxo carboxylic acids via decarboxylative coupling reaction. The target products could be obtained in moderate to high yields.