从产物分布的观点出发,已经研究了二锂联苯基(Li 2 C 12 H 10)与烷基氟化物的反应。两种主要的反应途径,亲核取代(S N 2)和电子转移(ET),可以竞争产生相同的烷基化产物,即所谓的S N 2–ET二分法。S N 2似乎是与伯烷基氟化物(n -RF)相互作用的主要机理。烷基化反应的收率很高,所得的烷基化二氢联苯阴离子(n -RC 12 H 10 Li)可以用第二种常规亲电试剂(E +),得到了合成上令人感兴趣的脱芳香化联苯衍生物(n -RC 12 H 10 E)。随着我们向仲(s -RF)和叔烷基氟化物(t -RF)的转移,反应产生了更多的ET产物,在这种情况下,该机理似乎主要由ET主导。在这种情况下,烷基化通过自由基偶合仍然可行,从而获得合成吨-RC 12 ħ 10 E,虽然在较低的产率。对这个S N的合理解释基于将5-己烯基氟化物和1,1-二甲基-5-己烯基氟化物用作与Li
(Trimethylsilylmethyl)trimethyldisilene was generated photochemically from 1-phenyl-7-trimethylsilylmethyl-7,8,8-trimethyl-7,8-disilabicyclo[2.2.2]octa-2,5-diene (masked disilene). UV spectrum and regioselectivity of the addition reaction of phenols to the disilene were discussed. The molecular structure of the masked disilene was also determined by single-crystal X-ray diffraction.
(Trimethylsilylmethyl)trimethyldisilene 是从 1-phenyl-7-trimethylsilylmethyl-7,8,8-trimethyl-7,8-disilabicyclo[2.2.2]octa-2,5-diene(掩蔽二硅烯)光化学生成的。讨论了酚类与二硅烷的加成反应的紫外光谱和区域选择性。掩蔽二硅烷的分子结构也通过单晶 X 射线衍射确定。
Paramagnetic solvent nuclear magnetic resonance shifts in radical anion solutions. 2. Some cation-dependent phenomena in concentrated solutions of aromatic hydrocarbon radical anions and dianions
作者:Constantinos G. Screttas、Maria Micha-Screttas
DOI:10.1021/jo00150a003
日期:1983.1
FREEMAN P. K.; HUTCHINSON L. L., J. ORG. CHEM., 1980, 45, NO 10, 1924-1930