Regio- and Stereochemistry of Bromochlorinations of Alkynes with Molecular Bromine Chloride and Dichlorobromate(1−) Ion
作者:Takeshi Negoro、Yoshitsugu Ikeda
DOI:10.1246/bcsj.59.3515
日期:1986.11
alkyl-substituted acetylenes with tetrabutylammonium dichlorobromate(1−) (1) in dichloromethane was found to be anti-stereospecific and nonregiospecific (regiospecific in the case of phenylacetylene). Whereas the addition of molecular bromine chloride (2) to phenyl-substituted acetylenes was found to give nonstereospecific and regiospecific adducts, the reaction of alkyl-substituted acetylenes gave anti-stereospecific
苯基和烷基取代的乙炔与二氯溴酸四丁基铵 (1-) (1) 在二氯甲烷中的溴氯化被发现是反立体特异性和非区域特异性的(在苯乙炔的情况下是区域特异性的)。发现将氯化溴分子 (2) 添加到苯基取代的乙炔中会产生非立体有择性和区域特异性的加合物,而烷基取代的乙炔的反应会产生反立体有择性和非区域性有选择性的加合物。这些结果表明,在产物形成阶段,添加 1 涉及氯离子对三中心 π 络合物的攻击,并且将 2 添加到苯基取代的乙炔涉及乙烯基阳离子中间体(但桥接溴鎓在烷基取代的乙炔的情况下为离子中间体)。