Metal-Free Synthesis of Unsymmetrical Ureas and Carbamates from CO<sub>2</sub> and Amines via Isocyanate Intermediates
作者:Yiming Ren、Sophie A. L. Rousseaux
DOI:10.1021/acs.joc.7b02905
日期:2018.1.19
A mild and metal-free synthesis of aryl isocyanates from arylamines under an atmosphere of CO2 was developed. The carbamic acid intermediate, derived from the arylamine starting material and CO2 in the presence of DBU, is dehydrated by activated sulfonium reagents to generate the corresponding isocyanate. The latter can be detected by in situ IR and trapped by various amines and alcohols to make unsymmetrical
开发了在CO 2气氛下由芳基胺温和无金属合成芳基异氰酸酯的方法。在DBU存在下,衍生自芳基胺原料和CO 2的氨基甲酸中间体通过活化的reagent试剂脱水,生成相应的异氰酸酯。后者可以通过原位红外检测,并被各种胺和醇捕获,分别制得不对称的脲和氨基甲酸酯。也可以通过相应的二氨基甲酸的温和脱水以高收率制备二氨基甲酸酯。