We report three different transformations in the reaction of the hydroxyamide-functionalized azolium chloride 1 with Ag₂O. These transformations were controlled by the N-substituent at the azolium ring of 1. Treatment of 1c (R = Me, alkyl) with Ag₂O afforded the corresponding monodentate NHC-Ag (NHC represents N-heterocyclic carbene) complex, 6c, in 95% yield. In contrast, the reaction of 1b (R = Ph, aryl) with Ag₂O yielded the corresponding 2-hydroxyoxazolidine-substituted azolium hydroxide, 7b, in 90% yield. In this transformation, perhaps the cyclization of the hydroxyamide moiety of 1b to 2-hydroxyoxazolidine occurred under the influence of the hydroxide counter anion. Several aryl-substituted azolium chlorides, 1d-f, were also converted into the corresponding cyclization products, 7d-f. However, the reaction of 1h (R = 2,4,6-Me₃C₆H₂, aryl) with Ag₂O afforded the corresponding NHC-Ag complex, 6h, in 93% yield, whereas the reaction of 1i (R = 4-MeOC₆H₄, aryl) with Ag₂O provided a mixture of 6i and 7i in 56% and 32% yields, respectively. Moreover, the reaction of azolium chloride, 1j (R = 2,6-ⁱPr₂C₆H₃, aryl), which has a more sterically hindered substituent at the ortho-position of the aryl side-arm, was investigated. Treatment of 1j with Ag₂O gave unexpected urea derivative, 8j, in 99% yield.

我们报道了在羟酰胺官能化的氯化azo 1与Ag ₂ O反应中的三种不同转化。这些转化受1的lium环上的N-取代基控制。用Ag ₂ O处理1c（R ＝ Me，烷基），得到95c收率的相应单齿NHC-Ag（NHC代表N-杂环卡宾）配合物6c。相反，1b（R = Ph，芳基）与Ag ₂ O反应生成相应的2-羟基恶唑烷取代的氢氧化偶氮鎓7b，产率为90％。在该转化中，也许1b的羟酰胺部分环化为2-羟基恶唑烷在氢氧根抗衡阴离子的影响下发生。几种芳基取代的偶氮氯化物1d - f也被转化为相应的环化产物7d - f。然而，1h（R = 2,4,6-Me ₃ C ₆ H ₂，芳基）与Ag ₂ O的反应得到了相应的NHC-Ag络合物6h，产率为93％，而1i（R = 4-MeOC ₆H ₄，芳基）与Ag ₂ O的混合物分别提供6i和7i的混合物，产率为56％和32％。此外，研究了在芳基侧臂的邻位具有更受空间阻碍的取代基的氯化偶氮氯化物1j（R = 2,6- ⁱ Pr ₂ C ₆ H ₃，芳基）的反应。用Ag ₂ O处理1j得到了出乎意料的尿素衍生物8j，产率为99％。