Diversified Aminohydantoins from Ureas and Thioureas Tethered to Amides
作者:Sukumar Bepary、In Kwon Youn、Hee-Jong Lim、Ge Hyeong Lee
DOI:10.1002/ejoc.201200025
日期:2012.5
Intramolecular cyclization of thioureas or ureastethered to amides afforded 2-iminohydantoins and 2-amino-1H-imidazol-4(5H)-ones in very high yields (87–100 %) regardless of the substituent (alkyls or aryls). This reaction proceeds through carbodiimides and iminium ions as intermediates. Among the reagents used to generate the carbodiimides, CBr4/Ph3P, CCl4/Ph3P, O,O′-bis(2′-pyridyl)thiocarbonate