Efficient regioselective synthesis of 4- and 5-substituted isoxazoles under thermal and microwave conditions
作者:Jamal Lasri、Suman Mukhopadhyay、M. Adflia Januário Charmier、M. Adflia Januário Charmier
DOI:10.1002/jhet.5570450521
日期:2008.9
The [2+3] cycloaddition reaction between nitrile oxides 2 and the captodative olefins 1 or the methyl crotonate derivatives 4 is regioselective and leads to the formation of the 5-substituted amino-isoxazole 3 or the 4-substituted methoxycarbonyl-isoxazole 5 derivatives, respectively. All these reactions are greatly accelerated by microwave irradiation without changing their regioselectivity with respect
腈氧化物2与俘获性烯烃1或巴豆酸甲酯衍生物4之间的[2 + 3]环加成反应是区域选择性的,并导致形成5-取代的氨基-异恶唑3或4-取代的甲氧基羰基-异恶唑5的衍生物,分别。微波辐照极大地加速了所有这些反应,而没有改变它们相对于热条件的区域选择性。