Benzopyranoimidazolones could virtually exist in four tautomeric forms, namely N3-H, N1-H, coumarin O-H, and C2-H. Experimental evidence reported thus far has been unable to lead to a unique statement about the preferred tautomeric forms in solution. In this work, tautomeric equilibria for a series of 2-substituted [1]benzopyrano[3,4-d]imidazol-4(3H)-ones were investigated by DFF calculations, in both gas phase and solution. The influence of the solvent was included in the calculations by the CPCM solvent model. C-13 chemical shifts of all tautomers were computed at different levels of theory and then compared with experiments to assign the preferred tautomers. Theoretical findings were then compared to dynamic H-1 NMR experiments results
Tautomeric equilibria of [1]benzopyrano[3,4-d]imidazol-4(3H)-ones, a theoretical and NMR study / A. Contini, D. Nava, P. Trimarco. - In: JOURNAL OF ORGANIC CHEMISTRY. - ISSN 0022-3263. - 71:1(2006 Jan 06), pp. 159-166. [10.1021/jo0519256]
Tautomeric equilibria of [1]benzopyrano[3,4-d]imidazol-4(3H)-ones, a theoretical and NMR study
A. ContiniPrimo
;D. NavaSecondo
;P. TrimarcoUltimo
2006
Abstract
Benzopyranoimidazolones could virtually exist in four tautomeric forms, namely N3-H, N1-H, coumarin O-H, and C2-H. Experimental evidence reported thus far has been unable to lead to a unique statement about the preferred tautomeric forms in solution. In this work, tautomeric equilibria for a series of 2-substituted [1]benzopyrano[3,4-d]imidazol-4(3H)-ones were investigated by DFF calculations, in both gas phase and solution. The influence of the solvent was included in the calculations by the CPCM solvent model. C-13 chemical shifts of all tautomers were computed at different levels of theory and then compared with experiments to assign the preferred tautomers. Theoretical findings were then compared to dynamic H-1 NMR experiments resultsPubblicazioni consigliate
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