147846-45-5Relevant academic research and scientific papers
Curtius rearrangement of aromatic carboxylic acids to access protected anilines and aromatic ureas
Lebel, Helene,Leogane, Olivier
, p. 5717 - 5720 (2006)
(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.
Intramolecular Aminoazidation of Unactivated Terminal Alkenes by Palladium-Catalyzed Reactions with Hydrogen Peroxide as the Oxidant
Beccalli, Egle M.,Broggini, Gianluigi,Foschi, Francesca,Lo Presti, Leonardo,Loro, Camilla,Oble, Julie,Poli, Giovanni,Sala, Roberto
supporting information, (2020/02/28)
The palladium-catalyzed aminoazidation of aminoalkenes yielding azidomethyl-substituted nitrogen-containing heterocycles was developed. The procedure requires oxidative conditions and occurs at room temperature in the presence of hydrogen peroxide and NaN3 as the azide source. These conditions provide selective exo-cyclization/azidation of the carbon-carbon double bond, furnishing a versatile approach toward five-, six-, and seven-membered heterocyclic rings.
Metal-Free Synthesis of Unsymmetrical Ureas and Carbamates from CO2 and Amines via Isocyanate Intermediates
Ren, Yiming,Rousseaux, Sophie A. L.
, p. 913 - 920 (2018/01/28)
A mild and metal-free synthesis of aryl isocyanates from arylamines under an atmosphere of CO2 was developed. The carbamic acid intermediate, derived from the arylamine starting material and CO2 in the presence of DBU, is dehydrated by activated sulfonium reagents to generate the corresponding isocyanate. The latter can be detected by in situ IR and trapped by various amines and alcohols to make unsymmetrical ureas and carbamates, respectively. Dicarbamates can also be prepared in good yields via the mild dehydration of the corresponding dicarbamic acids.
One-pot curtius rearrangement processes from carboxylic acids
Leogane, Olivier,Lebel, Helene
scheme or table, p. 1935 - 1940 (2009/12/29)
An efficient and practical synthesis of amine derivatives from carboxylic acids is described using new one-pot Curtius rearrangement processes. The preparation of carbamate-protected amines and anilines, as well as ureas was achieved in good to excellent yields on a multigram scale. Georg Thieme Verlag Stuttgart.
A modular flow reactor for performing Curtius rearrangements as a continuous flow process
Baumann, Marcus,Baxendale, Ian R.,Ley, Steven V.,Nikbin, Nikzad,Smith, Christopher D.,Tierney, Jason P.
experimental part, p. 1577 - 1586 (2008/10/09)
The use of a mesofluidic flow reactor is described for performing Curtius rearrangement reactions of carboxylic acids in the presence of diphenylphosphoryl azide and trapping of the intermediate isocyanates with various nucleophiles. The Royal Society of Chemistry 2008.
