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
One-Pot Preparation of 3-Arylisoxazole-4,5-dicarboxylates from Benzylic Chlorides and Acetylenedicarboxylates
作者:Taro Imai、Hideo Togo
DOI:10.1002/ejoc.201701726
日期:2018.3.22
N‐methylmorpholine N‐oxide (NMO) and then NH2OH·HCl and potassium carbonate followed by the addition of Oxone® in the presence of acetylene derivatives to give the corresponding 3‐arylisoxazole‐4,5‐dicarboxylates in good to moderate yields. This one‐pot transformation used readily available materials and was performed under transition‐metal‐free conditions.