New synthesis of 2-heteroarylperfluoropropionic acids derivatives by reaction of azine N-oxides with hexafluoropropene.
Hexafluoropropene reacts with aromatic azine N-oxides under mild conditions to produce fluorides of 2-heteroarylperfluoropropionic acids. The reaction proceeds as 1,3-dipolar cycloaddition followed by spontaneous scission of the N--O bond in the isoxazolidine ring and elimination of HF. When the reaction is carried out in the presence of alcohols or N-alkyl anilines, the in situ formed acyl fluorides give the corresponding esters and amides. They can be also treated separately with nucleophiles to produce the respective acylation products, whereas their hydrolysis leads to unstable carboxylic acids that undergo spontaneous decarboxylation to 1-aryl-1,2,2,2-tetrafluoroethanes. This new reaction provides a simple and general method of synthesizing 2-heteroarylperfluoropropionic acid derivatives that were previously unknown and unavailable.
Loska
Rafał
R
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw 42, Poland.
Makosza
Mieczysław
M
D000475:Alkenes / Q000737:chemistry; D001372:Aza Compounds / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry; D017611:Fluorine Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D005466:Fluorocarbons / Q000737:chemistry*; D015394:Molecular Structure; D010087:Oxides / Q000737:chemistry*; D011422:Propionates / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry
D000475:Alkenes; D001372:Aza Compounds; D002264:Carboxylic Acids; D017611:Fluorine Compounds; D005466:Fluorocarbons; D010087:Oxides; D011422:Propionates; D013438:Sulfhydryl Compounds; C031235:hexafluoropropene; C029658:propionic acid