title: Synthesis of isoxazoles by hypervalent iodine-induced cycloaddition of nitrile oxides to alkynes.
abstract: Treatment of oximes with hypervalent iodine leads to substituted isoxazoles via rapid formation of nitrile oxides. Reaction with terminal alkynes led to a series of 3,5-disubstituted isoxazoles with complete regioselectivity and high yield, in a procedure mild enough to prepare a range of nucleoside and peptide conjugates. Exceptionally high reaction rates were found for the formation of 3,4,5-trisubstituted isoxazoles from a cyclic alkyne.
authors.affiliation: Institute for Molecules and Materials, Radboud University Nijmegen, Heijendaalseweg 135, NL-6525 AJ, Nijmegen, The Netherlands.
authors.forename: Anup M
authors.initials: AM
authors.lastname: Jawalekar
authors.forename: Erik
authors.initials: E
authors.lastname: Reubsaet
authors.forename: Floris P J T
authors.initials: FP
authors.lastname: Rutjes
authors.forename: Floris L
authors.initials: FL
authors.lastname: van Delft
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D003500:Cyclization; D007455:Iodine / Q000737:chemistry*; D007555:Isoxazoles / Q000138:chemical synthesis / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D007555:Isoxazoles; D009570:Nitriles; D010087:Oxides; D007455:Iodine