THE REACTIONS OF 1,2,3-TRIAZOLIUM-1-IMIDES WITH DIPOLAROPHILES - KINETICS AND MECHANISM - AZOLIUM 1,3-DIPOLES

被引：19

作者：

BUTLER, RN ^{[1
]}

LYSAGHT, FA ^{[1
]}

BURKE, LA ^{[1
]}

机构：

[1] NATL UNIV IRELAND UNIV COLL GALWAY,DEPT CHEM,GALWAY,IRELAND

来源：

JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 | 1992年 / 07期

关键词：

D O I：

10.1039/p29920001103

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The reactions of substituted 1,2,3-triazolium-1-imides with dipolarophiles are dipole-HOMO controlled concerted cycloadditions. The second-order rate constants are insensitive to solvent polarity and the reaction shows a high negative entropy of activation. Substituent effects at the triazole carbon terminus of the dipole show a linear Hammett-sigma(p) correlation with p = 1.51. Substituents at the N-terminus of the dipole show a rare inverted V-type Hammett correlation with the reaction being dramatically inhibited by both MeO and NO2 groups. Dipolarophile variation suggests that triazolium imides are Type I dipoles. The regioselectivity of the reactions agree with ab initio calculated orbital coefficients and HOMO and LUMO energies.

引用

页码：1103 / 1106

页数：4