An I(2) promoted domino protocol was developed to construct 2-acylbenzothiazoles from simple and readily available aromatic ketones/unsaturated methyl ketones and o-aminobenzenethiols. The reaction proceeded smoothly under metal-free and peroxide-free conditions.
Oxidant/Solvent-Controlled I<sub>2</sub>-Catalyzed Domino Annulation for Selective Synthesis of 2-Aroylbenzothiazoles and 2-Arylbenzothiazoles under Metal-Free Conditions
作者:Renchao Ma、Yuxin Ding、Rener Chen、Zhiming Wang、Lei Wang、Yongmin Ma
DOI:10.1021/acs.joc.0c02095
日期:2021.1.1
A simple and practical domino protocol for the selective synthesis of 2-aroylbenzothiazoles and 2-aryl benzothiazoles catalyzed by I2 is developed under metal-free conditions. The reaction outcomes are exclusively controlled by the reaction oxidant/medium. With DMSO employed as both the solvent and the oxidant, an oxidation of aromatic methyl ketones takes precedence over the condensation with 2-aminobenzenethiols
A wide range of 2-aroylbenzothiazoles 3 including some pharmacologically, relevant derivatives can be obtained in high yields by simply heating o-halonitrobenzenes 1, acetophenones 2, elemental sulfur, and N-methylmorpholine. This three-component nitro methyl Coupling was found to occur in an excellent atom-, step-, an redox-efficient manner in which elemental sulfur prayed the role of nucleophile building block and redox moderating agent to fulfill electronic requirements of the global reaction.