Polar Effects. X. Polar Substituent Effects in the Solvolysis of 3-Substituted 1-Adamantyl Bromides and Toluenesulfonates
作者:Cyril A. Grob、Bruno Schaub
DOI:10.1002/hlca.19820650606
日期:1982.9.22
p-toluenesulfonates 3a-3k in ethanol/water 80:20 correlate well with the respective inductive substituent constants σ. The reaction constant ρ for the toluenesulfonates 3 is 10% larger than for the corresponding bromides 2, indicating somewhat more charge separation in the activation of the toluenesulfonates. Evidence is presented that stabilization of the resultant 1-adamantyl cations by induction involves graded
3-取代的金刚烷基对甲苯磺酸盐3a - 3k在乙醇/水80:20中的速率常数与各自的感应取代基常数σ紧密相关。甲苯磺酸盐3的反应常数ρ比相应的溴化物2大10%,这表明在甲苯磺酸盐的活化中电荷分离稍微更多。证据表明,通过感应稳定生成的1-金刚烷基阳离子涉及1,3-桥连,这在取代基为电离基团时是有利的,而正电子给体的稳定涉及C,C-超共轭。甲苯磺酸盐3和溴化物1的比率超过10 3,并且几乎独立于3个取代基。根据当前的假设,对此进行了讨论。