Herein, we report a metal-free radical tandem C–H amination and bromination reaction with dibromohydantoin (DBH) as both the amination and brominationreagents and water as the main solvent. The reaction involves in intramolecular C–H amination and electrophilicbromination using cheap commercially available DBH. The products represent heterocyclic building blocks, readily modifiable by classical cross-coupling
Herein, we report a metal-free and step-economic synthesis of iodo-dibenzothiazines from 2-biaryl sulfides under mild reaction conditions. The reaction involves sulfoximination of sulfides, intramolecular C–H amination, and iodization using cheap commercially available reagents. The products represent heterocyclic building blocks, readily modifiable by classical cross-coupling reactions.
Facial Syntheses of Bromobenzothiazines via Catalyst-Free Tandem C–H Amination/Bromination in Water
作者:Lixin Li、Yong Li、Zhengguang Zhao、Haotian Luo、Yan-Na Ma
DOI:10.1021/acs.orglett.9b02131
日期:2019.8.2
A transition-metal-free and environmentally friendly synthesis method for bromobenzothiazines through tandem C-H amination/bromination was reported. This reaction contains both intramolecular C-H amination and site-selective electrophilic bromination of arenes with NaBr as the bromo source, PhI(OAc)(2) or K2S2O8 as the oxidant, and H2O as the only solvent.