Department of Chemistry, Hope College, Holland, Michigan 49423, USA.
J Org Chem. 2013 Feb 15;78(4):1665-9. doi: 10.1021/jo302592g. Epub 2013 Jan 24.
An analysis of the palladium-catalyzed activation of carbon-carbon single bonds within triarylmethanols has led to a greater understanding of factors influencing the β-aryl elimination process responsible for C-C bond cleavage. A series of competition reactions were utilized to determine that β-aryl elimination of aryl substituents containing ortho-substitution proceeds with significant preference to unsubstituted phenyl rings. Further experiments indicate that substrates containing either strongly donating or withdrawing substituents are cleaved from triarylmethanols more readily than relatively neutral species.
对三芳基甲醇中碳-碳单键的钯催化活化进行了分析,这使得人们对影响负责 C-C 键断裂的β-芳基消除过程的因素有了更深入的了解。利用一系列竞争反应确定了邻位取代的芳基取代基的β-芳基消除反应具有明显的优势,有利于未取代的苯基环。进一步的实验表明,与相对中性的物质相比,含有强供电子或吸电子取代基的底物更容易从三芳基甲醇中裂解。