Aerobic, Transition-Metal-Free, Direct, and Regiospecific Mono-α-arylation of Ketones: Synthesis and Mechanism by DFT Calculations
作者:Qing-Long Xu、Hongyin Gao、Muhammed Yousufuddin、Daniel H. Ess、László Kürti
DOI:10.1021/ja4074563
日期:2013.9.25
We disclose a facile, aerobic, transition-metal-free, direct, and regiospecific mono-α-arylation of ketones to yield aryl benzyl and (cyclo)alkyl benzyl ketones with substitution patterns that are currently inaccessible or challenging to prepare using conventional methods. The transformation is operationally simple, scalable, and environmentally friendly. There is no need for pre-functionalization
我们公开了一种简便、有氧、无过渡金属、直接和区域特异性的酮单-α-芳基化,以产生芳基苄基和(环)烷基苄基酮,其取代模式目前无法使用常规方法制备或难以制备。转型操作简单、可扩展且环保。不需要预官能化(即α-卤化或甲硅烷基烯醇醚形成)或使用专门的芳基化剂(即二芳基碘盐)。DFT 计算表明,原位生成的烯醇化物与硝基芳烃直接形成 CC 键,然后进行区域选择性 O2 介导的 CH 氧化。
Copper-Assisted Direct Nitration of Cyclic Ketones with Ceric Ammonium Nitrate for the Synthesis of Tertiary α-Nitro-α-substituted Scaffolds
作者:Zhi-Qiang Zhang、Tao Chen、Fu-Min Zhang
DOI:10.1021/acs.orglett.7b00040
日期:2017.3.3
An efficient and direct Cu-assisted nitrating approach to create synthetically valuable and challenging tertiary α-nitro-α-substituted moieties has been developed using cericammoniumnitrate as a nitrating reagent, oxidant, and Lewis acid. Notably, the commonly used clinical drug ketamine was smoothly synthesized in four steps.
Porphyrins as Photoredox Catalysts in Csp<sup>2</sup>–H Arylations: Batch and Continuous Flow Approaches
作者:Aline A. N. de Souza、Nathalia S. Silva、Andressa V. Müller、André S. Polo、Timothy J. Brocksom、Kleber T. de Oliveira
DOI:10.1021/acs.joc.8b02355
日期:2018.12.21
We have investigated both batch and continuous flow photoarylations of enol-acetates to yield different α-arylated aldehyde and ketone building blocks by using diazonium salts as the aryl-radical source. Different porphyrins were used as SET photocatalysts, and photophysical as well as electrochemical studies were performed to rationalize the photoredox properties and suggest mechanistic insights.