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Ethyl‐2‐Cyano‐2‐(2‐Nitrophenylsulfonyloximino)Acetate ( ortho ‐NosylOXY) Mediated One‐Pot Racemization Free Synthesis of Ureas, Carbamates, and Thiocarbamates via Curtius Rearrangement
Author(s) -
Kalita Tapasi,
Dev Dharm,
Mondal Sandip,
Giri Rajat Subhra,
Mandal Bhubaneswar
Publication year - 2021
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.202100198
Subject(s) - chemistry , curtius rearrangement , racemization , thiocarbamates , amine gas treating , organic chemistry , reagent , yield (engineering) , saponification , combinatorial chemistry , metallurgy , materials science
Direct conversion of carboxylic acids to ureas, carbamates, and thiocarbamates in a single pot via Curtius rearrangement is accomplished. One recently established coupling reagent, Ethyl‐2‐cyano‐2‐(2‐nitrophenylsulfonyloximino)acetate ( o rtho‐NosylOXY, I ), is successfully used for the racemization free synthesis of ureas, di‐peptidyl ureas, and carbamates with moderate to good yield (82–69%). This single‐pot hassle‐free procedure works with a diverse range of N‐protecting groups Fmoc, Boc, and Cbz. Various amine, including aromatic, methyl esters of amino acids, t‐butylamine, alcohols, and thiols, are used as nucleophiles. A detailed NMR‐based mechanism study is incorporated here. Racemization suppression, easy removal of by‐products, and less waste generation make this methodology useful.