Transition state stucture and frontier orbital influence on the cycloaddition reactions of 2,5-dimethyl-3,4-dimethylenethiophene with styrenes and benzaldehydes
作者:Karl W. Haider、Jeffrey A. Clites、Jerome A. Berson
DOI:10.1016/s0040-4039(00)92371-2
日期:1991.9
reacts with styrenes and benzaldehydes to give fused cycloadducts. The effect of substituents on the efficiency of the benzaldehyde trapping reaction resembles that of normal electron-demand Diels-Alder reactions and is linear with the Hammett σ-constant. With the styrenes, the Hammett plot is non-linear. Frontier orbital theory provides a rationalization of these effects in terms of the uniquely HOMO-LUMO
双自由基的2,5-二甲基-3,4-二亚甲基噻吩与苯乙烯和苯甲醛反应生成稠合的环加合物。取代基对苯甲醛捕集反应效率的影响类似于正常的电子需求Diels-Alder反应,并且与Hammettσ常数呈线性关系。对于苯乙烯,哈米特图是非线性的。前沿轨道理论根据双自由基的独特HOMO-LUMO间隙特征提供了这些效应的合理化。