二氧化碳高值利用合成苯氨基甲酸甲酯

CO_(2)valorization through methyl N-phenylcarbamate synthesis

苯氨基甲酸甲酯(MPC)是合成二苯甲烷二异氰酸酯(MDI)的关键原料。以二氧化碳(CO_(2))及其等价物或衍生物作为碳源合成MPC代表了绿色和可持续的精细化学品合成方法。基于该领域研究,概述了基于CO_(2)转化合成苯氨基甲酸甲酯的研究方法进展。合成路线包括研究较多的CO_(2)等价物(尿素或苯基脲)醇解法,碳酸二甲酯(DMC)氨解法以及二苯基脲和DMC耦合反应法。另外,最理想的合成方法是近几年发展的苯胺、CO_(2)和甲醇三组分“一锅”反应法,以及使用脂肪胺类原料构建氨基甲酸烷基酯类化合物,其代表了最有前景的CO_(2)利用途径之一。详细探讨了反应机理和催化剂选择等问题。研究进展将为进一步提升绿色催化和可持续化学过程效率提供重要理论支持。

Methyl N-phenylcarbamate(MPC)is an important intermediate for the synthesis of diphenylmethane diisocyanate(MDI),and its preparation using CO_(2)or its equivalents/derivatives as carbon source represents a green and sustainable manner for fine chemicals synthesis.This review will highlight the development of MPC synthetic methods from the viewpoint of chemical fixation of CO_(2).The contents mainly include the introduction of MPC synthesis through CO_(2)equivalents(urea or phenyl urea)alcoholysis,dimethyl carbonate(DMC)aminolysis,and the coupling of DMC and diphenyl urea.Furthermore,one-pot synthesis of carbamates/MPC from aliphatic amines/aniline,CO_(2)and alcohols is highlighted which represents one of the most promising schemes in direct CO_(2)utilization.What is more,the reaction mechanisms and selection of catalysts are also discussed in detail.The advances will provide important theories on further improving the efficiency of green catalysis and sustainable chemical processes.