Influence of Alkyl Substitution on the Gas-Phase Stability of 1-Adamantyl Cation and on the Solvent Effects in the Solvolysis of 1-Bromoadamantane
作者:Ken'ichi Takeuchi、Takao Okazaki、Toshikazu Kitagawa、Takuhiro Ushino、Kenji Ueda、Tadasuke Endo、Rafael Notario
DOI:10.1021/jo0015265
日期:2001.3.1
1-Adamantyl cations having three methyl groups or one, two, or three isopropyl groups on the 3-, 5-, and 7-positions were found by FT ICR to be more stable than the 1-adamantyl cation and that the stability increases with the number of isopropyl group. The relative stabilities calculated by PM3 were in good agreement with the experimental results. In contrast, the sequence of the rates for the solvolysis
FT ICR发现在3-,5-和7位上具有三个甲基或一个,两个或三个异丙基的1-金刚烷基阳离子比1-金刚烷基阳离子更稳定,并且稳定性随着异丙基的数量。PM3计算的相对稳定性与实验结果吻合良好。相反,在非水溶剂中的溶剂分解速率顺序为3,5,7-(Me)(3)-1-AdBr <1-bromoadamantane(1-AdBr)<3,5,7-(n- Pr)(3)-1-AdBr <3,5,7-(i-Pr)(3)-1-AdBr。相对于1-AdBr在25度下3,5,7-(i-Pr)(3)-1-AdBr和3,5,7-(n-Pr)(3)-1-AdBr的溶剂分解速率EtOH中的C分别为15和3.8,但随着添加水量的增加而显着降低,在60%EtOH中分别达到0.84和0.15。反映水的这些影响,3,5,7-(i-Pr)(3)-1-AdBr和3,5,7-(n-Pr)(3)-1-AdBr与Y(Br)的Grunwal