1-Vinyl-1,2,2,3,3-pentafluorocyclopropane: an extraordinarily rapid vinylcyclopropane rearrangement
作者:Bruce E Smart、Paul J Krusic、D.Christopher Roe、Zhen-Yu Yang
DOI:10.1016/s0022-1139(02)00187-2
日期:2002.10
80–120 °C, and the activation parameters for the rearrangement of 1 to 2 are: kcal/mol, kcal/mol, and eu (log A=12.7, Ea=28.4 kcal/mol). Vinyl(pentafluorocyclopropane) (1) with a half-life of only 38 min at 110 °C, is one of the most thermally labile vinylcyclopropanes known. The isomeric E- and Z-1-propenyl-1,2,2,3,3-pentafluorocyclopropanes (3) similarly have relatively low activation parameters: ΔG‡(E)≅28
报道了1-乙烯基-1,2,2,3,3-五氟环丙烷(1)的合成及其热,单分子重排为1,4,4,5,5-五氟环戊烯的动力学(2)。动力学数据是通过气相NMR在80–120°C下获得的,重排1至2的活化参数为: kcal / mol, kcal / mol和 eu(log A = 12.7,E a = 28.4 kcal) / mol)。乙烯基(五氟环丙烷)(1)在110°C下的半衰期仅为38分钟,是已知的最不耐热的乙烯基环丙烷之一。异构体E-和Z-1-丙烯基-1,2,2,3,3-五氟环丙烷(3)同样具有相对较低的活化参数:ΔG ‡(E)≅28.5kcal / mol和ΔG ‡(Z)≅31.1kcal / mol。提出了用于重排的有利的极性双自由基过渡态,以解决这些烯基五氟环丙烷的异常反应性。