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Kinetics and Mechanism of the Pyridinolysis of Ethylene Phosphorochloridate in Acetonitrile

  • Received : 2011.10.05
  • Accepted : 2011.10.17
  • Published : 2011.12.20
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Abstract

The nucleophilic substitution reactions of ethylene phosphorochloridate (2) with X-pyridines are investigated kinetically in acetonitrile at $-20.0^{\circ}C$. The free energy correlations for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Ph. Unusual positive ${\rho}_X$ (= +2.49) and negative ${\beta}_X$ (= -0.41) values are obtained with the weakly basic pyridines, and rationalized by the isokinetic relationship with isokinetic temperature at $t_{ISOKINETIC}=6.6^{\circ}C$. The pyridinolysis rate of 2 with a cyclic five-membered ring is forty thousand times faster than its acyclic counterpart (3: diethyl chlorophosphate) because of great positive value of the entropy of activation of 2 (${\Delta}S^{\neq}$ = +49.2 eu) compared to negative value of 3 (${\Delta}S^{\neq}$ = -44.1 eu) over considerably unfavorable enthalpy of activation of 2 (${\Delta}H^{\neq}=28.4\;kcal\;mol^{-1}$) compared to 3 (${\Delta}H^{\neq}=6.3\;kcal\;mol^{-1}$). Great enthalpy and positive entropy of activation are ascribed to sterically congested transition state (TS) and solvent structure breaking in the TS. A concerted mechanism involving a change of nucleophilic attacking direction from a frontside attack with the strongly basic pyridines to a backside attack with the weakly basic pyridines is proposed.

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References

  1. Westheimer, F. H. Acc. Chem. Res. 1968, 1, 70. https://doi.org/10.1021/ar50003a002
  2. Gorenstein, D. G. Chem. Rev. 1987, 87, 1047. https://doi.org/10.1021/cr00081a009
  3. Yang, J. C.; Gorenstein, D. G. Tetrahedron 1987, 43, 479. https://doi.org/10.1016/S0040-4020(01)89980-4
  4. Barai, H. R.; Lee, H. W. Bull. Korean Chem. Soc. 2011, 32, in press.
  5. Dey, N. K.; Hoque, M. E. U.; Kim, C. K.; Lee, B. S.; Lee, H. W. J. Phys. Org. Chem. 2008, 21, 544. https://doi.org/10.1002/poc.1314
  6. Barai, H. R.; Lee, H. W. Bull. Korean Chem. Soc. 2011, 32, 3355. https://doi.org/10.5012/bkcs.2011.32.9.3355
  7. Hoque, M. E. U.; Dey, N. K.; Kim, C. K.; Lee, B. S.; Lee, H. W. Org. Biomol. Chem. 2007, 5, 3944. https://doi.org/10.1039/b713167d
  8. Dey, N. K.; Hoque, M. E. U.; Kim, C. K.; Lee, H. W. J. Phys. Org. Chem. 2010, 23, 1022. https://doi.org/10.1002/poc.1709
  9. Hoque, M. E. U.; Lee, H. W. Bull. Korean Chem. Soc. 2011, 32, 3505. https://doi.org/10.5012/bkcs.2011.32.9.3505
  10. Guha, A. K.; Lee, H. W.; Lee, I. J. Org. Chem. 2000, 65, 12. https://doi.org/10.1021/jo990671j
  11. Fischer, A.; Galloway, W. J.; Vaughan, J. J. Chem. Soc. 1964, 3591. https://doi.org/10.1039/jr9640003591
  12. Dean, J. A. Handbook of Organic Chemistry; McGraw-Hill: New York, 1987; Chapter 8.
  13. Lee, I.; Kim, C. K.; Han, I. S.; Lee, H. W.; Kim, W. K.; Kim, Y. B. J. Phys. Chem. B 1999, 103, 7302. https://doi.org/10.1021/jp991115w
  14. Coetzee, J. F. Prog. Phys. Org. Chem. 1967, 4, 45. https://doi.org/10.1002/9780470171837.ch2
  15. Jencks, W. P.; Brant, S. R.; Gandler, J. R.; Fendrich, G.; Nakamura, C. J. Am. Chem. Soc. 1982, 104, 7045. https://doi.org/10.1021/ja00389a027
  16. Onyido, I.; Swierczek, K.; Purcell, J.; Hengge, A. C. J. Am. Chem. Soc. 2005, 127, 7703. https://doi.org/10.1021/ja0501565
  17. Lee, I.; Lee, W. H.; Lee, H. W.; Bentley, T. W. J. Chem. Soc., Perkin Trans. 2 1993, 141.
  18. Chang, S.; Koh, H. J.; Lee, B. S.; Lee, I. J. Org. Chem. 1995, 60, 7760. https://doi.org/10.1021/jo00129a016
  19. Jencks, W. P. Chem. Rev. 1985, 85, 511. https://doi.org/10.1021/cr00070a001
  20. Bernasconi, C. F. Acc. Chem. Res. 1987, 20, 301. https://doi.org/10.1021/ar00140a006
  21. Bernasconi, C. F. Adv. Phys. Org. Chem. 1992, 27, 119.
  22. Gilliom, R. D. Introduction to Physical Organic Chemistry; Addison-Wesley; Philippines, 1970; pp 167-169.
  23. Dey, N. K.; Adhikary, K. K.; Kim, C. K.; Lee, H. W. Bull. Korean Chem. Soc. 2010, 31, 3856. https://doi.org/10.5012/bkcs.2010.31.12.3856
  24. Adhikary, K. K.; Lee, H. W. Bull. Korean Chem. Soc. 2011, 32, 1945. https://doi.org/10.5012/bkcs.2011.32.6.1945
  25. Hehre, W. J.; Random, L.; Schleyer, P. V. R.; Pople, J. A. Ab Initio Molecular Orbital Theory; Wiley: New York, 1986; Chapter 4.
  26. Lee, I. Chem. Soc. Rev. 1990, 19, 317. https://doi.org/10.1039/cs9901900317
  27. Lee, I. Adv. Phys. Org. Chem. 1992, 27, 57.
  28. Lee, I.; Lee, H. W. Collect. Czech. Chem. Commun. 1999, 64, 1529. https://doi.org/10.1135/cccc19991529
  29. Adhikary, K. K.; Lee, H. W.; Lee, I. Bull. Korean Chem. Soc. 2003, 24, 1135. https://doi.org/10.5012/bkcs.2003.24.8.1135

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