立体位阻效应导致的苯酚的区域选择性溴化（英文）

Steric Hindrance Effect Leading to Regioselective Bromination of Phenols with HBr

报道了苯酚与廉价易得的氢溴酸的区域选择性溴化反应.研究发现使用含有较大取代基的亚砜取代广为使用的二甲亚砜作为氧化剂,可以极大地提高反应的区域选择性,以中等至优秀的收率、高达99/1的区域选择性得到预期的溴代苯酚产物.该方法可以很容易放大到50 mmol级别,并且通过萃取与重结晶分离技术即可得到预期的溴代苯酚产物.

A mild and regioselective bromination of phenols with the cheap and easily-available HBr is developed.By replacing the common used dimethyl sulfoxide(DMSO)with sulfoxides bearing sterically hindered substituents,the desired brominated phenols could be obtained in moderate to high yields with up to 99/1 regioselectivity.This method could be easily scaled up to 50 mmol scale and has the potential to isolate the desired product by simple extraction and recrystallization,showing great practicality of this new method.