Abstract
The possibility of proton attack on various centers in pyrrolo[2,1-b]thiazole (1) has been evaluated. The results of semiempirical (MNDO, AM1, and PM3) andab initio (6-31G*) calculations were compared. The MNDO and 6-31G* methods give “chemically proper” and qualitatively coincident results. Analysis of the intramolecular (geometric and electronic) reorganization of molecule1, depending on the protonation center, has been carried out. The most probable attack centers, depending on the mechanism of electrophilic reaction, have been recognized. The energy parameters of intramolecular prototropic rearrangements in cation1 and the “blocking” factor value of methyl groups reducting the corresponding complex stability have been evaluated. It has been established that the relative stability of the protonated forms does not change on going to pyrrolo[2,1-b]selenium- and telluriumazoles, but the range of variations is considerably narrowed in the series S>Se>Te.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
A. G. Mal'kina, R. den Besten, A. C. H. M. van der Kerk, L. Brandsma, and B. A. Trofimov,J. Organomet. Chem., 1995,493, 271.
B. B. Molloy, L. Y. Reid, and S. MeKeszie,J. Chem. Soc., 1965, 4368.
M. J. S. Dewar and W. Thiel,J. Am. Chem. Soc., 1977,99, 4899.
M. J. S. Dewar, M. L. McKee, and H. S. Rzepa,J. Am. Chem. Soc., 1978,100, 3609.
M. J. S. Dewar, E. G. Zoebisch, E. F. Healy, and J. J. P. Stewart,J. Am. Chem. Soc., 1985,107, 3902.
M. J. S. Dewar and E. G. Zoebisch,J. Mol. Struct., 1988,180, 1.
J. J. P. Stewart,J. Comput. Chem., 1989,10, 209.
G. E. Chudinov, D. V. Napolov, and M. V. Basilevsky,Chem. Phys., 1992,160, 41.
M. V. Bazilevsky, G. E. Chudinov, and D. V. Napolov,Khim. Fiz., 1992,11, 691 [Chem. Phys., 1992,11 (Engl. Transl.)].
M. V. Basilevsky, G. E. Chudinov, D. V. Napolov, and L. M. Timofeeva,Chem. Phys., 1993,173, 345.
M. V. Sigalov, E. Yu. Shmidt, A. B. Trofimov, and B. A. Trofimov,Khim. Geterotsikl. Soedin., 1989, 1343 [Chem. Heterocycl. Compd., 1989 (Engl. Transl.)].
M. V. Sigalov, E. Yu. Shmidt, and B. A. Trofimov,Abstr. of 10th IUPAC Conference on Physical Organic Chemistry, Haifa (Israel), 1990, 59.
M. V. Sigalov, E. Yu. Shmidt, A. B. Trofimov, and B. A. Trofimov,Khim. Geterotsikl. Soedin, 1993, 823 [Chem. Hetereocycl. Compd., 1993 (Engl. Transl.)].
M. V. Sigalov, E. Yu. Shmidt, A. B. Trofimov, and B. A. Trofimov,J. Org. Chem., 1992,57, 3934.
M. V. Sigalov, A. B. Trofimov, E. Yu. Shmidt, and B. A. Trofimov,J. Phys. Org. Chem., 1993,6, 471.
A. B. Trofimov, B. A. Trofimov, N. M. Vitkovskaya, and M. V. Sigalov,Khim. Geterotsikl. Soedin., 1991, 746 [Chem. Heterocycl. Compd., 1991 (Engl. Transl.)].
M. V. Sigalov and B. A. Trofimov,Zh. Org. Khim., 1995,31, 801 [Russ. J. Org. Chem., 1995,31, (Engl. Transl.)].
Author information
Authors and Affiliations
Additional information
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1707–1711, October, 2000.
Rights and permissions
About this article
Cite this article
Shagun, V.A., Sinegovskaya, L.M., Toryashinova, D.S.D. et al. Quantum-chemical study of the protonation of pyrrolo[2,1-b]thiazole and its selenium and tellurium analogs. Russ Chem Bull 49, 1691–1695 (2000). https://doi.org/10.1007/BF02496335
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02496335