The Alkylation and Reduction of Heteroarenes with Alcohols Using Photoredox Catalyzed Hydrogen Atom Transfer via Chlorine Atom Generation
作者:Montserrat Zidan、Avery O. Morris、Terry McCallum、Louis Barriault
DOI:10.1002/ejoc.201900786
日期:2020.3.15
The alkylation of N‐heteroarenes using primary alcohols and ethers as radical precursors. The corresponding alkyl radical is formed via hydrogen atom transfer (HAT) process with a photoredox catalyzed chlorineatomgeneration as HAT agent. Furthermore, we explore the reduction of the heteroarenes when secondary alcohols are employed, giving moderate to high yields.
Ag-Catalyzed Remote Unactivated C(sp<sup>3</sup>)–H Heteroarylation of Free Alcohols in Water
作者:Miao Wang、Changzhen Yin、Peng Hu
DOI:10.1021/acs.orglett.0c03944
日期:2021.2.5
Catalyzed by silver salt, the unactivated C(sp3)–H heteroarylation of free alcohol at the δ position is realized under gentle thermal conditions in water through a radical procedure. Both protonic acids and Lewisacids are found to be efficient for activating pyridines for this Minisci-type reaction. The reaction enjoys a good functional group tolerance and substrate scope. Terminal secondary and tertiary
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。
The photochemical alkylation and reduction of heteroarenes
作者:T. McCallum、S. P. Pitre、M. Morin、J. C. Scaiano、L. Barriault
DOI:10.1039/c7sc03768f
日期:——
of transition-metal catalyzed processes that require initiators and stoichiometric oxidants. Herein, we describe the photochemical alkylation of quinolines, pyridines and phenanthridines, where through direct excitation of the protonated heterocycle, alcohols and ethers, such as methanol and THF, can serve as alkylating agents. We also report the discovery of a photochemical reduction of these heteroarenes