The Role of Structural Effects on the Reactions of Alkoxyl Radicals with Trialkyl and Triaryl Phosphites. A Time-Resolved Kinetic Study
作者:Massimo Bietti、Alessandra Calcagni、Michela Salamone
DOI:10.1021/jo100703b
日期:2010.7.2
kinetic study on the reactions of alkoxyl radicals with trialkyl and triaryl phosphites ((RO)3P: R = Me, Et, i-Pr, t-Bu; (ArO)3P: Ar = C6H5, 2,4-(t-Bu)2C6H3) has been carried out. In the (RO)3P series, the alkoxyl radicals (cumyloxyl (CumO•) and benzyloxyl (BnO•)) undergo addition to the phosphorus center with formation of intermediate tetraalkoxyphosphoranyl radicals (R′OP•(OR)3: R = Me, Et, i-Pr, t-Bu;
烷氧基与亚磷酸三烷基酯和亚磷酸三芳基酯((RO)3 P:R = Me,Et,i -Pr,t -Bu;(ArO)3 P:Ar = C 6 H 5,已经进行了2,4-(t- Bu)2 C 6 H 3)。在(RO)3 P系列中,烷氧基(枯基氧基(CumO •)和苄氧基(BnO •))加入磷中心,形成中间四烷氧基磷杂烷基(R'OP •(OR)3:R = Me ,等等,i -Pr,t -Bu; R'= Bn,总和)。添加速率常数受空间效应的影响,从R = Me到R = t -Bu以及从BnO •到CumO •降低。还确定了磷烷基基团R'OP •(OR)3的β断裂速率常数,对于给定的烷基R,按下列顺序增加:R'=叔丁基