Unusual anisotropic effects from 1,3-dipolar cycloadducts of 4-azidomethyl coumarins
作者:Raviraj A. Kusanur、Manohar V. Kulkarni、Geetha M. Kulkarni、Susanta K. Nayak、Tayur N. Guru Row、Kilivelu Ganesan、Chung-Ming Sun
DOI:10.1002/jhet.273
日期:——
acetone to give 4-azidomethylcoumarins (), which underwent 1,3-dipolar cycloaddition with acetylenic dipolarophiles to give triazoles (). These triazoles () have been found to exhibit interesting variations in the chemical shifts of C3H and C4-methylene protons. Protonation studies indicate that the shielding effect of the C3H of coumarin is due to π-electrons of the triazole ring, further supported
4-溴甲基香豆素()与 丙酮水溶液中的叠氮化钠制得4-叠氮甲基香豆素(),然后与炔属双极性亲和剂进行1,3-偶极环加成反应,得到三唑()。这些三唑业已发现)在C 3 H和C 4-亚甲基质子的化学位移方面表现出有趣的变化。质子化研究表明,香豆素C 3 H的屏蔽作用归因于三唑环的π电子,这进一步受到衍射和计算研究的支持。J.杂环化学.2010。