Metal-, Photocatalyst-, and Light-Free Direct C–H Acylation and Carbamoylation of Heterocycles
作者:Matthew T. Westwood、Claire J. C. Lamb、Daniel R. Sutherland、Ai-Lan Lee
DOI:10.1021/acs.orglett.9b02679
日期:2019.9.6
Direct C-H acylations and carbamoylations of heterocycles can now be readily achieved without requiring any conventional metal, photocatalyst, electrocatalysis, or light activation, thus significantly improving on sustainability, costs, toxicity, waste, and simplicity of the operational procedure. These mild conditions are also suitable for gram-scale reactions and late-stage functionalizations of
Highly Regioselective Carbamoylation of Electron-Deficient Nitrogen Heteroarenes with Hydrazinecarboxamides
作者:Zeng-Yang He、Chao-Fan Huang、Shi-Kai Tian
DOI:10.1021/acs.orglett.7b02312
日期:2017.9.15
The use of hydrazinecarboxamides as a new class of carbamoylating agents has been established through the dehydrazinative Minisci reaction of electron-deficient nitrogen heteroarenes. A wide range of electron-deficient nitrogen heteroarenes, including isoquinoline, quinoline, pyridine, phenanthridine, quinoxaline, and phthalazine, underwent copper/acid-catalyzed oxidative carbamoylation with hydrazinecarboxamide
nucleophilic carbon-centered radicals is furtheron developed by the following new achievements: i) utilization of the redoc system in several solvents; ii) utilization of benzoyl peroxide in alcohols; iii) carbamoylation by HCONH2 and H2O2 in the presence of catalytic amounts of Fe(II). These systems allow to obtain either substitution till now tried without success or reactions of industrial interest.
下列新成果进一步发展了质子化杂芳族碱基被亲核碳中心自由基直接取代的综合兴趣:ii)酒精中过氧化苯甲酰的利用;iii)在催化量的Fe(II)存在下通过HCONH 2和H 2 O 2进行氨基甲酰基化。这些系统允许获得直到现在为止一直没有成功的替代方案,或者获得工业利益的反应。极性效应在确定反应性,选择性和合成应用方面起主要作用;特别强调了吡啶基类型的强亲核中间基团在重新麦芽糖化步骤中的作用。
A novel and mild source of carbon-centered radicals by iodosobenzene diacetate (IBDA) and sodium azide from alcohols, ethers, aldehydes, amides and alkyl iodides
作者:Francesca Fontana、Francesco Minisci、Ming Yan Yong、Zhao Lihua
DOI:10.1016/s0040-4039(00)60456-2
日期:1993.4
A radical process for the thermal decomposition of IBDA in the presence of sodium azide; by this method, carbon centered radicals can be generated either by hydrogen abstraction from the solvent (an alcohol, an ether, an aldehyde or formamide) or by iodine abstraction from alkyliodides.
The functionalisation of various heterocyclicbases induced by sunlight is reported. The photoreaction occurred with higher yield in a liquid-solid heterogeneous system in the presence of polycrystalline TiO2 (anatase) than in a homogeneous system under the same experimental conditions.