Polar Effects. Part 15. Twin γ-substituent effects in the formation of adamantyl-1-cations
作者:Cyril A. Grob、Martin Gründel、Pawel Sawlewicz
DOI:10.1002/hlca.19880710615
日期:1988.9.28
adamant-1-yl ( = tricyclo[3.3.1.13,7]dec-1-yl) p-toluenesulfonates and bromides 2 identically substituted at C(3) and C(5) (twin substitution) have been determined and compared with the rates of the corresponding 3-monosubstituted compounds 1. As expected, the rate factors for twin substitution are much larger, but less than the square of the rate factors for single substitution. Also the rates factors
几个在C(3)和C(5)相同取代的金刚烷基-1-基(=三环[3.3.1.1 3,7 ]癸-1-基)对甲苯磺酸盐和溴化物2的溶剂分解速率已经达到确定并与相应的3-单取代化合物的比率进行比较。如预期的那样,双取代的比率因子要大得多,但小于单取代的比率因子的平方。同样,2中每个替代品的费率因子比1中一个替代品的费率因子小得多。该衰减归因于电子排斥,该电子排斥限制了电子密度向阳离子中心的收敛。在另一方面,对于双取代的电感(ρ 1 = -2.55)是大约两倍高为单取代(ρ 1 = -1.26)。