results on the chemistry of persistent vinylcations are summarized. β, β-Disilyl-substituted vinylcations were synthesized by intramolecular addition of transient silylium ions to alkynes. The vinylcations are stable at ambient temperature and were isolated in the form of their tetrakispentafluorophenylborate and hexabromocarboranate salts. The vinylcations were characterized by IR and NMR spectroscopy
总结了关于持久性乙烯基阳离子化学的最新结果。β, β-二甲硅烷基取代的乙烯基阳离子是通过将瞬态甲硅烷离子分子内加成到炔烃上来合成的。乙烯基阳离子在环境温度下是稳定的,并以其四五氟苯基硼酸盐和六溴碳硼酸盐的形式被分离出来。乙烯基阳离子通过IR和NMR光谱以及X射线晶体学表征。α-烷基-和 α-芳基-取代的乙烯基阳离子的实验结果证实了它们的 Y 形结构,由线性双配位、形式上带正电荷的 α-碳原子和三角平面配位的 /α-碳原子组成。此外,光谱数据清楚地表明了这些乙烯基阳离子中 /α-甲硅烷基超共轭的后果。
STEINMETZ, MARK G.;UDAYAKUMAR, B. S., J. ORGANOMET. CHEM., 378,(1989) N, C. 1-15
作者:STEINMETZ, MARK G.、UDAYAKUMAR, B. S.
DOI:——
日期:——
Chloroplatinic acid catalyzed cyclization of silanes bearing pendant acetylenic groups
作者:Mark G. Steinmetz、B.S. Udayakumar
DOI:10.1016/0022-328x(89)85001-6
日期:1989.11
Chloroplatinicacidcatalyzed, intramolecular hydrosilylation of acetylenes of structure HMe2Si[CH2]nSiMe2CCR (R H or Ph, n = 2 or 3) proceeds via syn addition of the SiH group to the carbon triple bond to give, predominantly, cyclic products having an exocyclic rather than an endocyclic double bond. When n = 1 (R H), only recovered starting material is obtained. Closure of (4-hexynyl)dimethylsilane