An Adjusted Model for Simple 1,2-Dyotropic Reactions. Ab Initio MO and VB Considerations

DOI: 10.4236/ojpc.2013.33015   PDF   HTML     2,421 Downloads   4,117 Views   Citations


With an adjusted model, we reconsider simple 1,2-dyotropic reactions with the introduction of a concept based on the intramolecular dynamics of a tetrahedron (van ’t Hoff modeling). In fact the dyotropic reactions are strongly related to conversions originated from neighbouring group participation or anchimeric assistance, defined as the interaction of a center with a lone pair of electrons in an atom and the electrons present in aδor π bond. The researchful 1,2-dyotropic reactions, based on the 1,2-interchange of halogens, methyl and hydrogen taking place in a concerted fashion, are in competition with the two-step reaction in which the neighbouring group participation or anchimeric assistance comes to full expression by ionic dissociation of the other exchangeable (halogen) atom. As to be expected there is an essential difference between halogen or methyl exchange regarding the number of electrons participating in the transition state. This aspect becomes evident in the geometries of the corresponding transition state geometries. In this paper we refer to ab initio MO calculations and VB considerations. We consider the 1,2-halogen exchange as a combination of two SN2 reactions each containing four electrons. The van ’t Hoff dynamics appears a useful model in order to illustrate the computations in a straightforward manner.

Share and Cite:

H. Buck, "An Adjusted Model for Simple 1,2-Dyotropic Reactions. Ab Initio MO and VB Considerations," Open Journal of Physical Chemistry, Vol. 3 No. 3, 2013, pp. 119-125. doi: 10.4236/ojpc.2013.33015.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] M. T. Reetz, “Dyotropic Rearrangements, a New Class of Orbital-Symmetry Controlled Reactions. Type I,” Angewandte Chemie International Edition in English, Vol. 11, No. 2, 1972, pp. 129-130. doi:10.1002/anie.197201291
[2] I. Fernández, F. P Cossío and M. A. Sierra, “Dyotropic Reactions: Mechanisms and Synthetic Applications,” Chemical Reviews, Vol. 109, No. 12, 2009, pp. 6687-6711. doi:10.1021/cr900209c
[3] H. M. Buck, “A Combined Experimental, Theoretical, and Van ’t Hoff Model Study for Identity Methyl, Proton, Hydrogen Atom, and Hydride Exchange Reactions. Correlation with Three-Center Four-, Three-, and Two-Electron Systems,” International Journal of Quantum Chemistry, Vol. 108, No. 9, 2008, pp. 1601-1614. doi:10.1002/qua.21683
[4] H. M. Buck, “A Linear Three-Center Four Electron Bonding Identity Nucleophilic Substitution at Carbon, Boron, and Phosphorus. A Theoretical Study in Combination with Van ’t Hoff Modeling,” International Journal of Quantum Chemistry , Vol. 110, No. 7, 2010, pp. 1412-1424. doi:10.1002/qua
[5] I. Fernández, F. M. Bickelhaupt and F. P. Cossío, “Type-I Dyotropic Reactions: Understanding Trends in Barriers,” Chemistry—A European Journal, Vol. 18, No. 39, 2012, pp. 12395-12403. doi:10.1002/chem.201200897
[6] I. Fernández, M. A. Sierra and F. P. Cossío, “Stereoelectronic Effects on Type I 1,2-Dyotropic Rearrangements in Vicinal Dibromides,” Chemistry—A European Journal, Vol. 12, No. 24, 2006, pp. 6323-6330. doi:10.1002/chem.200501517
[7] M. N. Glukhovtsev, A. Pross and L. Radom, “Gas-Phase Identity SN2 Reactions of Halide Anions with Methyl Halides. A High-Level Computational Study,” Journal of the American Chemical Society, Vol. 117, No. 7, 1995, pp. 2024-2032. doi:10.1021/ja00112a016
[8] H. M. Buck, “A Model Investigation of Ab Initio Geometries for Identity and Nonidentity Substitutions with ThreeCenter Fourand Three-Electron Transition States,” International Journal of Quantum Chemistry, Vol. 111, No. 10, 2011, pp. 2242-2250. doi:10.1002/qua.22529
[9] T. H. Lowrey and K. S. Richardson, “Mechanism and Theory in Organic Chemistry,” Harper & Row, New York, 1976.
[10] A. P. Bento and F. M. Bickelhaupt, “Nucleophilicity and Leaving-Group Ability in Frontside and Backside SN2 Reactions,” The Journal of Organic Chemistry, Vol. 73, No. 18, 2008, pp. 7290-7299. doi:10.1021/jo801215z
[11] D. H. R. Barton and A. J. Head, “Long-Range Effects in Alicyclic Systems. Part I. The Rates of Rearrangement of Some Steroidal Dibromides,” Journal of the Chemical Society, 1956, pp. 932-937. doi:10.1039/jr9560000932
[12] C. A. Grob and S. Winstein, “Mechanismus der Mutarotation von 5, 6-Dibromcholestan,” Helvetica Chimica Acta, Vol. 35, No. 3, 1952, pp. 782-802. doi:10.1002/hlca.19520350315
[13] L. Radom, J. A. Pople, V. Buss and P. V. R. Schleyer, “Molecular Orbital Theory of the Electronic Structure of Organic Compounds. XI. Geometries and Energies of C3H7 Cations,” Journal of the American Chemical Society, Vol. 94, No. 2, 1972, pp. 311-321. doi:10.1021/ja00757a001
[14] P. R. Schreiner, D. L. Severance, W. L. Jorgensen, P. von Schleyer and H. F. Schaefer III, “Energy Difference between the Classical and the Nonclassical 2-Norbornyl Cation in Solution. A Combined Ab Initio—Monte Carlo Aqueous Solution Study,” Journal of the American Chemical Society, Vol. 117, No. 9, 1995, pp. 2663-2664. doi:10.1021/ja00114a037
[15] G. A. Olah, G. K. S. Prakash, á. Molnár and J. Sommer, “Superacid Chemistry,” 2nd Edition, John Wiley & Sons, Inc., Hoboken, 2009. doi:10.1021/ja00114a037
[16] J. Strating, J. H. Wieringa and H. Wynberg, “The Isolation of a Stabilized Bromonium Ion,” Journal of the Chemical Society D Chemical Communications, No. 16, 1969, pp. 907-908.
[17] H. M. Buck, “Mechanistic Models for the Intramolecular Hydroxycarbene-Formaldehyde Conversion and Their Intermolecular Interactions: Theory and Chemistry of Radicals, Mono-, and Dications of Hydroxycarbene and Related Configurations,” International Journal of Quantum Chemistry, Vol. 112, No. 23, 2012, pp. 3711-3719. doi:10.1002/qua.24127
[18] H. M. Buck, “Trigonal Pyramidal Carbon Geometry as Model for Electrophilic Addition-Substitution and Elimination Reactions and Its Sinificance in Enzymatic Processes,” International Journal of Quantum Chemistry, Vol. 107, No. 1, 2007, pp. 200-211. doi:10.1002/qua.21061
[19] D. F. Shellhamer, D. C. Gleason, S. J. Rodriguez, V. L. Heasley, J. A. Boatz and J. J. Lehman, “ Correlation of Calculated Halonium Ion Structures with Product Distributions from Fluorine substituted Terminal Alkenes,” Tetrahedron, Vol. 62, No. 50, 2006, pp. 11608-11617. doi:10.1016/j.tet.2006.09.071
[20] G. A. Olah, G. Rasul, M. Hachoumy, A. Burrichter and G. K. S. Prakash, “ Diprotonated Hydrogen Halides (H3X2+) and Gitonic Protio Methyland Dimethylhalonium Dications (CH3XH22+ and (CH3)2XH2+). Theoretical and Hydrogen-Deuterium Exchange Studies,” Journal of the American Chemical Society, Vol. 122, No. 12, 2000, pp. 2737-2741. doi:10.1021/ja994044n
[21] M. D. Struble, M. T. Scerba, M. Siegler and T. Lectka, “Evidence for a Symmetrical Fluoronium Ion in Solution,” Science, Vol. 340, No. 6128, 2013, pp. 57-60. doi:10.1126/science.1231247
[22] A. Streitwieser Jr. and C. H. Heathcock, “Introduction in Organic Chemistry,” 3rd Edition, Macmillan Publishing Company, New York, 1985. doi:10.1126/science.1231247

comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.