Remarkable Effect of Water on Functionalization of the Phenyl Ring in Methyl-Substituted Benzene Derivatives with F-TEDA-BF<sub>4</sub>
作者:Petra Kralj、Marko Zupan、Stojan Stavber
DOI:10.1021/jo060213s
日期:2006.5.1
reagents reacted with hexamethylbenzene (1) forming side chain substituted alkoxides or esters in protic solvents, Ritter type side chain functionalization was observed in acetonitrile in the presence of trifluoroacetic acid, while in aqueous acetonitrile solution phenyl ring transformation took place, starting with ipso attack of water and further rearrangement of the methyl group as the main process. Rearranged
各种NF试剂与六甲基苯(1)在质子溶剂中反应形成侧链取代的醇盐或酯,在三氟乙酸存在下在乙腈中观察到Ritter型侧链官能化,而在乙腈水溶液中发生苯环转化,开始以ipso攻击水和进一步重新排列甲基为主要过程。重排的2,3,4,5,6,6-六甲基环己-2,4-二烯酮(7)被转化为5-氟-2,3,5,6,6-五甲基-4-亚甲基环己基-2-en- 1-酮(8)或5-羟基-2,3,5,6,6-五甲基-4-亚甲基环己基-2-烯-1-酮(9)。1,2,3,4,5,6-六甲基双环[2.2.0] hexa-2,5-二烯与F-TEDA-BF 4反应在水的存在下,以高收率形成7。Durene(12)对水的ipso攻击行为与1类似,但另一方面1,2,3,4-四甲基苯具有不同的区域选择性,并形成2,3,4,5-四甲基苯酚,进一步转化为4-氟- 2,3,4,5-四甲基环己-2,5-二烯酮。遵守二阶速率方程v = d [NF]