(Z)-1,2-二苯基-1,3-丁二烯与单取代的乙烯衍生物区位选择性环加成反应

Regiosclective Cycloaddition Reaction of (Z)-1 ,2-Diphcnyl-1 ,3-butadiene with Monosubstituted Ethylenes

(Z)-1,2-二苯基-1,3-丁二烯分别与甲基乙烯基酮、丙烯酰胺、丙烯腈以及丙烯醛发生环加成反应,均生成顺式和反式的连位取代环己烯衍生物。以IR、~1H NMR和MS鉴定了产物的结构。利用CNDO/2法计算了分子轨道能量和系数,由前线分子轨道理论解释了这种环加成反应的区位选择性。

The cycloaddition reactions of (Z)-J ,2-diphenyl-1, 3-butadiene were studied with a high regioselectivity. The products were identified by IR, NMR and MS. The regioselectivity in the Diels-Alder reactions of (Z)-1 ,2-diphenyl-1 ,3-butadiene can be rationalized by frontier orbital theory. The primary orbital interactions which have been used to predict the regioselectivity in the Diels-Alder reaction could not account for the regioselectivity observed with (Z)-1,2-diphenyl-1,3-butadiene. When the secondary orbital interactions were included in the theory, the preferred regioisomer was rationalized in every case. The frontier molecular orbitals of (Z)-1, 2-diphenyl-1, 3-butadiene and the dienophiles were determined by the CNDO/2 method.