Activation of Pentafluorophenylsilanes by Weak Lewis Bases in Reaction with Iminium Cations
作者:Alexander D. Dilman、Vitalij V. Levin、Miriam Karni、Yitzhak Apeloig
DOI:10.1021/jo0606812
日期:2006.9.1
The Lewis base mediated carbon−carbon bond forming reactions between pentafluorophenylsilanes and iminium cations were studied theoretically and experimentally. The complexation of silanes with anionic Lewis bases was analyzed computationally using DFT methods at the B3LYP/6-31+G(d) level. The pentafluorophenyl group was found to exhibit a significant stabilizing effect on the formation of pentacoordinate
理论上和实验上研究了路易斯碱介导的五氟苯基硅烷与亚胺阳离子之间的碳-碳键形成反应。使用DFT方法在B3LYP / 6-31 + G(d)水平上对硅烷与阴离子路易斯碱的络合进行了计算分析。发现五氟苯基对五配位硅物质的形成表现出显着的稳定作用,其中(C 6 F 5)3 SiF和C 6 F 5 SiF 3是最强的路易斯酸。三角双锥硅醇R作为几何异构体的比较2(C 6 ˚F 5)SiXY -(R = Me,F,Cl; X,Y = F,Cl,ClO 4)表明,杂原子和C 6 F 5基团分别倾向于占据顶部和赤道位置。的C计算6 ˚F 5从硅烷到基转移过程Ñ,Ñ采用弱路易斯碱X时(1):-dimethyliminium阳离子导致以下结论- =氯-,CLO 4 -作为活化剂,R 2(C 6 ˚F 5)SiF比R 2(C 6 F 5)SiX(X = Cl,ClO 4); (2)C 6 F 5基团在顶端位置的