Ethyl 2-Cyano-2-(4-nitrophenylsulfonyloxyimino)acetate-Mediated Lossen Rearrangement: Single-Pot Racemization-Free Synthesis of Hydroxamic Acids and Ureas from Carboxylic Acids
Ethyl 2-cyano-2-(4-nitrophenylsulfonyloxyimino)acetate (4-NBsOXY) mediated Lossenrearrangement and its application for the synthesis of ureas is demonstrated. Required hydroxamic acids for the Lossenrearrangements were synthesized from carboxylic acids using the same reagent. Finally, reaction of an amine with the produced isocyanate resulted in urea. Good yields without racemization were achieved
Tf<sub>2</sub>O‐Promoted Synthesis of Ureas, Carbamates and Thiocarbamate via Lossen Rearrangement: A Mechanistic Insight
作者:Eti Chetankumar、Chinthaginjala Srinivasulu、Ganga Periyasamy、Vommina V. Sureshbabu
DOI:10.1002/ejoc.202400028
日期:2024.4.15
A new and feasible synthetic method for ureas, carbamates and thiocarbamate from hydroxamic acid and Tf2O via Lossen rearrangement has been developed. The use of Tf2O was chemoselective with hydroxamate group with broad substrate applicability and good functional group tolerance. Further pathway of the mechanism was analysed through computational studies.