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
4-Dodecylbenzenesulfonic acid (DBSA) promoted solvent-free diversity-oriented synthesis of primary carbamates, S-thiocarbamates and ureas
作者:Ali Reza Sardarian、Iman Dindarloo Inaloo
DOI:10.1039/c5ra14528g
日期:——
A simple and efficient solvent-free preparation of primary carbamates,S-thiocarbamates and ureas from alcohols, phenols, thiols and amines in the presence of 4-dodecylbenzenesulfonic acid, as a cheap and green Brønsted acid, has been described.
Rhodium(II)-Catalyzed Undirected and Selective C(sp<sup>2</sup>)–H Amination en Route to Benzoxazolones
作者:Ritesh Singh、Kommu Nagesh、Matam Parameshwar
DOI:10.1021/acscatal.6b02237
日期:2016.10.7
promote the activation and cyclization of arylcarbamate substrates to yield benzoxazolones via an intramolecular nitrene C–H insertion reaction. Investigation of the substrate scope shows that the reaction undergoes selective aromatic C(sp2)—H amination over more labile o-C(sp3)—Hbonds. Observation of inverse secondary KIE (PH/PD = 0.42 ± 0.03) indicates involvement of aromatic electrophilic substitution
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。