Synthesis of alpha-trifluoromethyl-beta-lactams and esters of beta-amino acids via 1,3-dipolar cycloaddition of nitrones to fluoroalkenes.
Nitrones derived from aromatic or aliphatic aldehydes or ketones react with hexafluoropropene (HFP) or 2H-pentafluoropropene (PFP) to give the respective fluorinated isoxazolidine derivatives in good yields with complete regioselectivity and moderate diastereoselectivity. Catalytic hydrogenolysis of the N-O bond under ambient pressure and temperature leads to fluorides of beta-amino acids that undergo cyclization to alpha-trifluoromethylated beta-lactams or, under acidic conditions, form esters of alpha-trifluoromethylated beta-amino acids.
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
Jakub
J
Jakowiecki
Rafał
R
Loska
Mieczysław
M
Makosza
D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry*; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D017611:Fluorine Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007555:Isoxazoles / Q000737:chemistry; D008745:Methylation; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D013237:Stereoisomerism; D047090:beta-Lactams / Q000138:chemical synthesis* / Q000737:chemistry
D000475:Alkenes; D000596:Amino Acids; D004952:Esters; D017611:Fluorine Compounds; D007555:Isoxazoles; D009589:Nitrogen Oxides; D010087:Oxides; D047090:beta-Lactams; C015388:nitrones; D010100:Oxygen