Synthesis of Symmetrical and Unsymmetrical Ureas Using Unsymmetrical Diaryl Carbonates
作者:Richard Freer、Alexander McKillop
DOI:10.1080/00397919608003622
日期:1996.1
Abstract Appropriately substituted unsymmetrical diaryl carbonates react smoothly with primary amines to give the carbamates derived by nucleophilic displacement of the less electron rich aromatic substituent. Subsequent treatment of the carbamates with primary and secondary amines gives either symmetrical or unsymmetrical ureas in excellent yield and the overall process can be carried out as a “one
摘要 适当取代的不对称碳酸二芳基酯与伯胺反应平稳,通过亲核置换较少富电子的芳族取代基得到氨基甲酸酯。随后用伯胺和仲胺处理氨基甲酸酯,以极好的收率得到对称或不对称的脲,整个过程可以作为“一锅”操作进行。乙腈是优选的溶剂,加入 DBU 有利于氨基甲酸酯 → 尿素的转化。