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

摘要

An effective three-component fixation of atmospheric CO2 with readily available 1,2-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-dichloroethane (e.g. 1,2-dichloropropane and 2,3-dichlorobutane). The catalytic system is not sensitive to air and moisture, and high yield of oxazolidinone was achieved even with about 0.3atm of pressure of carbon dioxide. The mechanistic study suggests that the reaction catalyze by in situ NHC via NHC-CO2 adduct, 1-butyl-3-methylimidazolium-2-carboxylate as intermediate and aminochloride involves in reaction pathways. The catalyst can be recycled for at least 3times 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 1,3-dichloropropane and 1,4-dichlorobutane was employed.