Ethyl‐2‐Cyano‐2‐(2‐Nitrophenylsulfonyloximino)Acetate (ortho‐NosylOXY) Mediated One‐Pot Racemization Free Synthesis of Ureas, Carbamates, and Thiocarbamates via Curtius Rearrangement. Issue 6 (20th May 2021)

• Record Type: Journal Article
• Authors: Kalita, Tapasi; Dev, Dharm; Mondal, Sandip; Giri, Rajat Subhra; Mandal, Bhubaneswar
• Is Part Of: Asian journal of organic chemistry. Volume 10:Issue 6(2021)
• Page Start: 1523
• Page End: 1529
• Publication Date: 2021-05-20
• Subjects: Curtius rearrangement -- ureas -- carbamates -- thiocarbamates -- o-NosylOXY -- racemization free; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; 547.005
• DOI: 10.1002/ajoc.202100198
• Languages: English
• ISSNs: 2193-5807

Abstract

Abstract: 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. Abstract : A convenient racemization‐free method for urea, carbamate, and thiocarbamate synthesis using ethyl‐2‐cyano‐2‐(2‐nitrophenylsulfonyloximino)acetate ( ortho ‐NosylOXY) is described.