Oxidation of unsymmetrically sunstituted 1,3-diarylpropynones in a system trifluoroacetic acid-dichloromethane-lead(IV) oxide proceeds through intermediate formation of cation radicals and occurs regio- and stereoselectively affording E-1,1,2,2-tetraaroylethenes. The highest yield of these compounds was obtained from 1,3-diarylpropynones containing electron-donor methoxy and methyl groups in the aromatic ring conjugated with the triple bond.
不对称取代的1,3-二芳基
丙炔酮在
三氟乙酸-
二氯甲烷-四
氧化铅体系中氧化,经过阳离子自由基中间体的形成,进行区域和立体选择性反应,生成E-1,1,2,2-四芳基
乙烯。这些化合物的最高产率来自于含有与三键共轭的电子供体甲氧基和甲基基团的1,3-二芳基
丙炔酮。