中文摘要：

应用半经验的AM1和密度泛函B3LYP/6-31G＊方法对1,3-丁二烯与C59XH（X=N,B）Diels-Alder环加成反应的区域选择性进行理论研究,选择一些有代表性的C59XH（X=N,B）的6—6键探讨环加成反应的机理.1,3-丁二烯与C59NH进行的Diels-Alder反应,随着加成位置远离C59NH的N原子,活化能越来越低,但都比1,3-丁二烯与C60相应反应的活化能高.与此相反,对于1,3-丁二烯与C59BH进行的环加成反应,加成位置最靠近B原子的2,12/r-和2,12/f-过渡态的势垒最低,并且比1,3-丁二烯与C60进行环加成反应的活化能约低18kJ·mol^-1,其产物也是热力学最稳定的.与C60相应的反应相比,C59NH和C59BH中N和B原子不同的电子性质对其邻位双键进行Diels-Alder环加成反应的活性产生了不同影响,前者使反应活性降低,后者使反应活性增强.

英文摘要：

The regioselectivity of Diels-Alder cycloaddition of 1,3-butadiene to C59XH （X=N, B） has been studied theoretically by means of the semiempirical AM1 and DFF （B3LYP/6-31G ＊） methods. The mechanisms of the cycloaddition on some selected 6-6 bonds of C59XH （X=N, B） have been analyzed. For C59NH, the activation energies become lower with the addition site increasingly farther from the N atom; however, they are all higher than that of the reaction of 1,3- butadiene with C60 In contrast to C59NH, for the cycloaddition to C59BH, the activation energies corresponding to 2,12/r- and 2,12/f- transition states, in which the addition sites are the nearest ones to the B atom, are the lowest ones,and are lower than that of the reaction of 1,3-butadiene with Coo by over 18 kJ. mol 2, and the products corresponding to these two transition states are the most stable ones. The different electronic natures of N and B atoms results in different effects on the Diels-Alder reactions of 1,3-butadiene with C59NH and C59BH; the former makes the reactivity of C59NH reduced and the latter makes the reactivity of C59BH enhanced, relative to that of C60.