N,N′-Diarylsquaramides: General, High-Yielding Synthesis and Applications in Colorimetric Anion Sensing
摘要:
Zinc trilluoromethanesullonate promotes efficient condensations of anilines with squarate esters, providing access to symmetrical and unsymmetrical squaramides in high yields from readily available starting materials. Efficient access to electron-deficient diaryl squaramides has enabled a systematic investigation of the colorimetric anion-sensing behavior of a p-nitro-substituted squaramide. Its behavior differs in dramatic and unexpected ways from that of structurally similar p-nitroaniline-based ureas, an effect that highlights the remarkable differences in acidity between the squaramide and urea functional groups. Computational studies illustrating the enhanced hydrogen bond donor ability and acidity of squaramides in comparison to ureas are presented.
<i>N</i>,<i>N′</i>-Diarylsquaramides: General, High-Yielding Synthesis and Applications in Colorimetric Anion Sensing
作者:Ali Rostami、Alexis Colin、Xiao Yu Li、Michael G. Chudzinski、Alan J. Lough、Mark S. Taylor
DOI:10.1021/jo100104g
日期:2010.6.18
Zinc trilluoromethanesullonate promotes efficient condensations of anilines with squarate esters, providing access to symmetrical and unsymmetrical squaramides in high yields from readily available starting materials. Efficient access to electron-deficient diaryl squaramides has enabled a systematic investigation of the colorimetric anion-sensing behavior of a p-nitro-substituted squaramide. Its behavior differs in dramatic and unexpected ways from that of structurally similar p-nitroaniline-based ureas, an effect that highlights the remarkable differences in acidity between the squaramide and urea functional groups. Computational studies illustrating the enhanced hydrogen bond donor ability and acidity of squaramides in comparison to ureas are presented.