132431-13-1Relevant articles and documents
Curtius rearrangement of aromatic carboxylic acids to access protected anilines and aromatic ureas
Lebel, Helene,Leogane, Olivier
, p. 5717 - 5720 (2007/10/03)
(Diagram presented) The reaction of a chloroformate or di-tert-butyl dicarbonate and sodium azide with an aromatic carboxylic acid produces the corresponding acyl azide, presumably through the formation of an azidoformate. The acyl azide undergoes a Curtius rearrangement to form an isocyanate derivative which is trapped either by an alkoxide or by an amine to form the aromatic carbamate or urea. The reaction conditions are compatible with a variety of functional groups and allow the synthesis of a number of aniline derivatives containing alkyl, halide, nitro, ketone, ether, and thioether substituents.
Boron trifluoride promoted cleavage of benzyl carbamates
Subhas Bose,Thurston, David E.
, p. 6903 - 6906 (2007/10/02)
A new efficient method for the cleavage of benzyl carbamates (CBZ protective groups) is described that involves a hard acid (BF3·OEt2) - soft nucleophile (EtSH) system. Unlike other available methods, this combination avoids the reduction of olefins, acetylenes, imines, halides and nitro groups, or the possibility of carboxylic ester hydrolysis.
