铑(II)可以通过分子内的氮杂C–H插入反应有效地促进芳基氨基甲酸酯底物的活化和环化,从而生成苯并恶唑啉酮。对底物范围的研究表明,该反应在更不稳定的o -C(sp 3)-H键上进行了选择性芳族C(sp 2)-H胺化反应。反向二次KIE的观察结果(P H / P D = 0.42±0.03)表明,芳族亲电取代机理参与了芳基CH酰胺化反应。
structurally diverse compounds containing a hydroxyl group has been performed in high yields and purity, and without any epimerization undersolvent-freeconditions using HClO4–SiO2 as a mild, convenient, and effective reagent. The procedure is operationally simple, efficient, and environmentally benign.
The dynamic 1H NMRstudy of some primary carbamates in the solvents CDCl3 and CD3COCD3 between 183 and 298 K is reported. The free energies of activation, thus obtained (12.4 to 14.3 kcal mol-1), were attributed to the conformational isomerization about the N−C bond. These barriers to rotation show solvent dependence in contrast to the tertiary analogues and are lower in free energy by ca. 2−3 kcal