Unusual Reactivity of 4-Vinyl Isoxazoles in the Copper-Mediated Synthesis of Pyridines, Employing DMSO as a One-Carbon Surrogate
作者:Pravin Kumar、Manmohan Kapur
DOI:10.1021/acs.orglett.0c01935
日期:2020.8.7
An efficient protocol for the synthesis of nicotinate derivatives and tetrasubstituted pyridines through a copper-mediated cleavage of isoxazoles has been developed. The highlight of the work is the observation of an unusualreactivity of 4-vinyl isoxazoles under the reaction conditions. DMSO serves as a one-carbon surrogate generating an active methylene group during the reaction to form two C–C bonds
Reactions of β-diketones with hydroxylamine hydrochloride; synthesis of 3,5-disubstituted isoxazoles
作者:J. Larkin、M. G. Murray、D. C. Nonhebel
DOI:10.1039/j39700000947
日期:——
Substituted dibenzoylmethanes react with hydroxylaminehydrochloride to give 3-aryl-5-phenylisoxazoles and/or 5-aryl-3-phenylisoxazoles depending on the nature of the substituent in the diketone. Some structures previously assigned to isoxazoles from these reactions have been shown to be incorrect.