Determination of aromaticity indices of thiophene and furan by nuclear magnetic resonance spectroscopic analysis of their phenyl esters
作者:Chang Kiu Lee、Ji Sook Yu、Hye-Jin Lee
DOI:10.1002/jhet.5570390615
日期:2002.11
series of m- and p-substituted phenyl benzoates, 2-thienoates, and 2-furoates were prepared and their 1H and 13C nmr spectroscopic characteristics were examined. In general, good correlations were observed between the chemical shift values of protons and carbons of the acyl aromatic rings and the Hammett σ. Plots of the chemical shift values of the carbonyl carbons of the benzoates against those of
A novel Cu(0)-Cu(I)-mediated Caryl-Caryl Ullmann coupling has been successfully developed. The use of Cu(I) salts allowed the reactions to proceed under relatively mild conditions (65 °C in DMSO for 15–72 h). The developed method was compatible with a relatively wide range of functional groups simultaneously present on the aromatic ring of different electronic nature. The aryl halides with an electron-withdrawing