Synthesis of Oxazolidinones and Derivatives through Three‐Component Fixation of Carbon Dioxide

Congmin Mei; Yibo Zhao; Qianwei Chen; Changsheng Cao; Guangsheng Pang; Yanhui Shi

Index: 10.1002/cctc.201800142

Full Text: HTML

Abstract

An effective three‐component fixation of atmospheric CO2 with readily available dichloroethane and aromatic amine toward oxazolidinones catalyzed by in‐situ NHC was developed. The reaction occurred in good to excellent yields with good generality and wide functional group tolerance, including challenging steric hindered substituted‐dichloroehane (e.g. 1,2‐dichloropropan and 2,3‐dichlorobutane). The catalytic system is not sensitive to air and moisture, and high yield of oxazolidinone was achieved even with about 0.3 atm of pressure of carbon dioxide. The mechanistic study suggests that the reaction catalyze by in‐situ NHC via CO2‐NHC adduct, 1‐n‐butyl‐3‐methylimidazolium‐2‐carboxylate as intermediate and aminochloride involves in reaction pathways. The catalyst can be recycled for at least 3 times without obvious loss of catalytic activity. The protocol is also effective to prepare six‐membered 3‐aryl‐1,3‐oxazinan‐2‐one and even seven‐membered 3‐aryl‐1,3‐oxazepan‐2‐one, when dichloropropane and dichlorobutane was employed.