Structural Effects on the β-Scission Reaction of Alkoxyl Radicals. Direct Measurement of the Absolute Rate Constants for Ring Opening of Benzocycloalken-1-oxyl Radicals
作者:Massimo Bietti、Osvaldo Lanzalunga、Michela Salamone
DOI:10.1021/jo048026m
日期:2005.2.1
The absolute rate constants for β-scission of a series of benzocycloalken-1-oxyl radicals and of the 2-(4-methylphenyl)-2-butoxyl radical have been measured directly by laser flash photolysis. The benzocycloalken-1-oxyl radicals undergo ring opening with rates which parallel the ring strain of the corresponding cycloalkanes. In the 1-X-indan-1-oxyl radical series, ring opening is observed when X =
通过激光闪光光解法直接测量了一系列苯并环烯-1-氧基和2-(4-甲基苯基)-2-丁氧基的β-断裂的绝对速率常数。苯并环烯-1-氧基自由基以与相应环烷烃的环应变平行的速率开环。在1-X-茚满-1-氧基自由基系列中,当X = H,Me时,观察到开环,而当X = Et时,发生独家CX键断裂。讨论了控制片段区域选择性的因素。