Investigation of the lability of furan and its derivatives in nucleophilic substitution reactions by the mindo/3 method

The a complexes of furan, thiophene, pyrrole, pyridine, and benzene with the hydride ion were calculated by the MINDO/3 method. The affinities of the indicated aromatic rings and a number of substituted furans for the H^– ion were estimated. It is shown that the relative magnitude of the affinity correlates qualitatively with the experimental data on the relative rates of the reaction of the examined compounds with nucleophilic reagents. The following order of increasing reactivities of unsubstituted aromatic rings was obtained: pyrrolethiophene. The effect of various types of substituents in various positions on the tendency of the five-membered ring to undergo nucleophilic substitution is discussed.Translated from Khimiya Geterotsikli-cheskikh Soedinenii, No. 12, pp. 1598–1603, December, 1979.This research was accomplished with a Siemens-4004 computer (West Germany) in the computer center of J. Komensky Bratislava University (Czechoslovakian SSR). The authors thank I. Goler for his assistance in performing the calculations.Original article submitted February 27, 1979.