New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
J Org Chem. 2020 Dec 4;85(23):15422-15436. doi: 10.1021/acs.joc.0c02216. Epub 2020 Nov 13.
An efficient new synthesis of 3,5-bis(het)arylisoxazoles, involving the reaction of 1,3-bis(het)arylmonothio-1,3-diketones with sodium azide in the presence of IBX catalyst, has been reported. The reaction proceeds at room temperature in high yields and is applicable to a broad range of substrates including the synthesis of 5-methyl-3-arylisoxazoles, a key subunit present in several β-lactamase-resistant antibiotics. A probable mechanism for the formation of isoxazoles has been suggested. A few of the 5-styryl/arylbutadienyl-3-(het)arylisoxazoles have also been synthesized by reacting the corresponding 1-(het)aryl-1-(methylthio)-4-(het)arylidene-but-1-en-3-ones with sodium azide at higher temperatures. The reaction of β-ketodithioesters with sodium azide is shown to furnish β-ketonitriles in good yields.
一种高效的合成 3,5-双（杂）芳基异恶唑的新方法，涉及 1,3-双（杂）芳基单硫-1,3-二酮与叠氮钠在 IBX 催化剂存在下的反应。该反应在室温下进行，产率高，适用于广泛的底物，包括 5-甲基-3-芳基异恶唑的合成，该化合物是几种β-内酰胺酶抗性抗生素中的关键亚基。提出了异恶唑形成的可能机制。通过在较高温度下用相应的 1-（杂）芳基-1-（甲硫基）-4-（杂）芳基亚甲基-1-丁烯-3-酮与叠氮钠反应，也合成了一些 5-苯乙烯基/芳基丁二烯基-3-（杂）芳基异恶唑。β-二硫代酯与叠氮钠的反应以良好的产率得到β-酮腈。
