Ortho versus α-Metalation of Ethyl Phenyl Sulfide by <i>n-</i>Butyllithium/<i>N</i>,<i>N</i>,<i>N</i>‘,<i>N</i>‘<i>-</i>Tetramethylethylenediamine: Synthesis, Reactivity, and Crystal Structures of (2-(Ethylthio)phenyl)- and (1-(Phenylthio)ethyl)lithium
ortho phenyl carbon atoms. The distorted-tetrahedral donor set of Li is completed by two nitrogen atoms (tmeda). Furthermore, from solutions of 4 in n-hexane crystals of [Li(CHMeSPh)(tmeda)}2(μ-tmeda)] (5‘) were obtained. X-ray structure analysis revealed the presence of centrosymmetric dimers. The primary donor set of Li is made up of one carbon atom and three nitrogen atoms, two of them from a chelating
n- BuLi / tmeda(tmeda = N,N,N ',N'-四甲基乙二胺)对乙基苯硫醚的金属化反应强烈依赖于溶剂。在正-己烷和乙醚邻锂化发生,得到(2-(乙基硫基)苯基)锂,而在四氢呋喃发生(THF)α位锂化,得到(1-(苯硫基)乙基)锂。从Ñ己烷溶液[李(C 6 H ^ 4 SET-2)乙二胺(TMEDA)} 2 ](4)分离,为白色粉末。4在THF中的溶解导致异构化,定量形成α-锂化化合物[Li(CHMeSPh)(tmeda)](5)。化合物4和5与n- Bu 3 SnCl反应,分别得到n- Bu 3 Sn(C 6 H 4 SEt-2)(1a)和n- Bu 3 SnCHMeSPh(2a)。的标识4,5,图1A和2A,确认通过1个H,13 C,和119的Sn(1A / 2A)。NMR测量。的单晶X射线衍射分析4表明它是二聚体,具有由两个锂原子和两个邻苯基碳原子组成的非平面四元
Oxidative Generation of Thioalkyl Cations from 2-Tributylstannyl-1,3-dithianes and 1-(Tributylstannyl)alkyl Sulfides and Their Reactions with Olefinic Nucleophiles
作者:Koichi Narasaka、Noriyoshi Arai、Tatsuo Okauchi
DOI:10.1246/bcsj.66.2995
日期:1993.10
2-Tributylstannyl-1,3-dithianes and 1-(tributylstannyl)alkyl sulfides are oxidized with ammoniumhexanitratocerate(IV) or ferrocenium hexafluorophosphate to generate their cation radicals, which dissociate into the carbocations and tributylstannyl radical. The carbocations thus generated react with olefinic nucleophiles to afford the corresponding addition products in good yield.