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苯硫酚与1-苯基丙炔-1及1-苯基丁炔-1在苯甲酰过氧化物或紫外光引发下顺利加成.当反应物用量为等克分子比时,加成物分别为1-苯基-2-苯硫基丙烯-1(Ⅰ)及1-苯基-2-苯硫基丁烯-1(Ⅱ);当用量为2∶1克分子比时,除生成上述1∶1加成物外,尚得2∶1加成物:1-苯基-2,2-二-(苯硫基)-丙烷(Ⅴ)及1-苯基-2,2-二-(苯硫基)-丁烷(Ⅵ).这些加成物的结构是借在酸性介质中与2,4-二硝基苯肼作用生成相应酮的2,4-二硝基苯腙而得到证明.这加成反应是按自由基机理进行,苯硫基联结在与烷基相邻的碳原子表明中间生成的自由基之稳定性是加成方向的决定因素,因为苯基的共轭效应比烷基为强. 竞争试验的结果表明,苯硫基对苯乙炔的加成比对1-苯基丙炔-1的加成快得多,这可归因于甲基的空间效应.当以苯硫酚与1-苯基丙炔-1及苯乙烯进行竞争时,只得炔烃的加成物,这表明炔烃的加成活性比烯烃大得多.后一结果是由于断裂三键中的一个π-键所需要的能量较断裂双键中的π-键所需要的能量为低的缘故.
Thiophenol and 1-phenyl-propyne-1 and 1-phenyl-butyne-1 in the benzoyl peroxide or UV-induced smooth addition when the amount of reactants equal molar ratio, the addition of The compounds were 1-phenyl-2-phenylthio-1 (I) and 1-phenyl-2-phenylthiobutene-1 In addition to the above 1: 1 adduct, 2: 1 adducts were obtained: 1-phenyl-2,2-di- (phenylthio) -propane (V) and 1-phenyl- (Phenylthio) -butane (VI). The structure of these adducts is obtained by the action of 2,4-dinitrophenylhydrazine in an acidic medium to produce the corresponding ketone 2,4-dinitrophenylhydrazone This addition reaction is based on the free radical mechanism and the attachment of the phenylthio group at the carbon atom adjacent to the alkyl group indicates that the stability of the intermediate generated radicals is the determining factor of the addition direction since the total amount of phenyl groups The yoke effect is stronger than the alkyl group.The results of the competition test showed that the addition of phenylthio-p-phenylacetylene was much faster than the addition of 1-phenylpropyne-1 due to the spatial effect of methyl When competing with 1-phenylpropyne-1 and styrene with thiophenol, only an alkyne adduct was obtained, indicating that the addition activity of the alkyne is higher than that of the olefin The latter result is due to the fact that the energy required for one π-bond in the cleaved triple bond is lower than the energy required for the π-bond in the cleaved double bond.