A Transition Metal-Free Minisci Reaction: Acylation of Isoquinolines, Quinolines, and Quinoxaline
摘要:
Transition metal-free acylation of isoquinoline, quinoline, and quinoxaline derivatives has been developed employing a cross dehydrogenative coupling (CDC) reaction with aldehydes using substoichiometric amount of TBAB (tetrabutylammonium bromide, 30 mol %) and K2S2O8 as an oxidant. This intermolecular acylation of electron-deficient heteroarenes provides an easy access and a novel acylation method of heterocyclic compounds. The application of this CDC strategy for acylation strategy has been illustrated in synthesizing isoquinoline-derived natural products.
Remote site-selective C–H activation directed by a catalytic bifunctional template
作者:Zhipeng Zhang、Keita Tanaka、Jin-Quan Yu
DOI:10.1038/nature21418
日期:2017.3
In chemical syntheses, the activation of carbon–hydrogen (C–H) bonds converts them directly into carbon–carbon or carbon–heteroatom bonds without requiring any prior functionalization. C–Hactivation can thus substantially reduce the number of steps involved in a synthesis. A single specific C–H bond in a substrate can be activated by using a ‘directing’ (usually a functional) group to obtain the desired
Copper-Catalyzed Selective 1,2-Dialkylation of N-Heteroarenes via a Radical Addition/Reduction Process: Application for the Construction of Alkylated Dihydroazaarenes Derivatives
作者:Qiu Sun、Yuan-Yuan Zhang、Jing Sun、Ying Han、Xiaodong Jia、Chao-Guo Yan
DOI:10.1021/acs.joc.8b00928
日期:2018.6.15
of various N-heteroarenes was developed with ether and alkylhalide at ambient temperature. This transformation involves the combination of oxidative coupling by Cu/TBHP and reduction process by 1,8-diazabicyclo[5.4.0]undec-7-ene. This method provides an efficient method to prepare various substituted dihydroazaarene derivatives via a free-radical process.
A new procedure for the carbonylative acetylation of heterocycles has been developed. In this process, organic peroxide acts as the methyl source, various heterocycles were transformed into the corresponding methyl heterocyclic ketones in moderate to good yields.
Radical C−H Acylation of Nitrogen Heterocycles Induced by an Aerobic Oxidation of Aldehydes
作者:Subhasis Paul、Manotosh Bhakat、Joyram Guin
DOI:10.1002/asia.201900857
日期:2019.9.16
ketones is described herein. The reaction involves cross-dehydrogenative coupling between aldehydes and heteroaromatic bases with molecularoxygen (O2 ). The key aspect of the method is the generation of reactive acyl radical via homolytic activation of aldehyde C-H bond using O2 as the sole oxidant. The reaction has a good substrate scope with respect to aldehydes and functionalized nitrogen heterocycles
Microwave-assisted C-C cross-coupling reactions of aryl and heteroaryl halides in water
作者:Kamal M. Dawood、Moteaa M. El-Deftar
DOI:10.3998/ark.5550190.0011.930
日期:——
The catalytic activity of a benzimidazole-oxime Pd(II)-complex towards Suzuki and Heck C-Ccross-couplingreactions of activated and deactivated aryl- and heteroaryl bromides under microwave irradiation as well as thermal heating using water as a green solvent was evaluated. The turnover frequency reached 420,000 under microwave condition.
评估了苯并咪唑-肟 Pd(II)-配合物在微波照射下以及使用水作为绿色溶剂的热加热下对 Suzuki 和 Heck CC 交叉偶联反应的活化和失活芳基溴化物和杂芳基溴化物的催化活性。微波条件下周转次数达到42万次。