作者:Andrey V. Bogolubsky、Sergey V. Ryabukhin、Sergey E. Pipko、Oleg Lukin、Alexander Shivanyuk、Dmytro Mykytenko、Andrey Tolmachev
DOI:10.1016/j.tet.2011.03.101
日期:2011.5
versatile method for the synthesis of unsymmetricalureas from readily available reagents is reported. In the first step trifluoroethylchloroformate is reacted with a stoichiometric amount of a primary amine to give an intermediate trifluoroethyl carbamate. The addition of a second amine (primary or secondary) to the trifluoroethyl carbamate furnishes corresponding unsymmetricalureas in 75–85% yield. A