115466-16-5Relevant articles and documents
Sulfur–Fluoride Exchange (SuFEx)-Mediated Synthesis of Sterically Hindered and Electron-Deficient Secondary and Tertiary Amides via Acyl Fluoride Intermediates
Smedley, Christopher J.,Barrow, Andrew S.,Spiteri, Christian,Giel, Marie-Claire,Sharma, Pallavi,Moses, John E.
, p. 9990 - 9995 (2017/08/01)
Amide bond formation is one of the most executed reactions in chemistry and biology. This is largely due to the ubiquity of the amide functional group in biological molecules, natural products and pharmaceutically important drugs. We report here the development of “SuFExAmide”: a new sulfur–fluoride exchange (SuFEx) click chemistry based protocol for the efficient amidation of carboxylic acids via acyl fluoride intermediates. We have developed benzene-1,3-disulfonyl fluoride as a cost effective, powerful and versatile coupling agent, which delivers challenging secondary and tertiary amides in excellent yields from sterically hindered and electron-deficient amines. The straightforward method offers significant benefits over existing protocols in terms of substrate scope, efficiency and ease of operation and is demonstrated by the synthesis of 44 amides, including GNF6702, an antiprotozoal drug candidate. In the majority of cases, the amide products are obtained in high yield without the need for excess reagents or chromatographic purification.
Gold catalysis: Products and intermediates obtained from N-propargylcarboxamides bearing additional substituents on nitrogen
Hashmi, A. Stephen K.,Molinari, Lise,Rominger, Frank,Oeser, Thomas
experimental part, p. 2256 - 2264 (2011/06/19)
The reaction of several propargylamide substrates with additional substituents on the nitrogen atom was investigated. Under aqueous conditions acyloxy-substituted allylammonium salts could selectively be obtained. Monitoring of the reactions by 1H NMR spectroscopy indicated the presence of an intermediate. Then switching to anhydrous reaction conditions allowed the isolation and characterization of these intermediates, oxazoliniminium species. Workup of the allylammonium salts under basic conditions led to an acyl transfer from the oxygen atom to the nitrogen atom, which proves that these products are not formed by a direct gold-catalysed hydration of the triple bond only, and at the same time nicely explains the selective monohydration of only one out of two triple bonds. A careful control of the conditions allows the synthesis of either oxazolinum salts oracyloxy-substituted enynes with an ammonium unit in the tether. The latter compounds are stable in the presence of the gold catalyst; they do not undergo a gold-catalysed enyne cycloisomerization. Copyright
