Bromination of Norbornene: the Question of Bromonium Ions <i>vs</i>. 6,1-Hydride Shift
作者:D. R. Marshall、P. Reynolds-Warnhoff、E. W. Warnhoff、J. R. Robinson
DOI:10.1139/v71-148
日期:1971.3.15
a radical mechanism. The product composition from the bromine addition has been compared with that of the analogous chlorination and bromofluorination reactions. Degradation of the 2-exo,3-endo-dibromonorbornane from bromination of 5,6-14C-norbornene has shown that this dibromide is formed by two ionic routes: (a) from a bromonium ion 14 (or its equivalent), and (b) from the cation 12 formed by 6,1-hydride
对降冰片烯 (1) 与溴的反应进行了重新研究,发现除了溴代降冰片烯 (2) 和 2-外型溴代降冰片烷 (20) 之外,还会产生一种复杂的二溴化物混合物,其中已分离出五种 (15-19)并确定。已发现这些二溴化物是离子加成的动力学控制产物。显然,二溴化物 15 也在一定程度上通过自由基机制在四氯化碳中形成。溴加成的产物组成与类似的氯化和溴氟化反应的产物组成进行了比较。2-exo,3-endo-dibromonorbornane 从 5,6-14C-降冰片烯的溴化中降解表明,这种二溴化物是通过两种离子途径形成的:(a)从溴离子 14(或其等价物),和( b) 由 6,1-氢化物转变形成的阳离子 12。