Narzędzia help

Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników
first last
cannonical link button

http://yadda.icm.edu.pl:80/baztech/element/bwmeta1.element.baztech-article-BUJ5-0005-0041

Czasopismo

Polish Journal of Chemistry

Tytuł artykułu

tert-Butylimino-tris(dimethylamino)phosphorane as a Proton Acceptor in the System of Reaction of 1-Nitro-1-(4-nitrophenyl)alkanes in THF

Autorzy Wisłocka, I.  Nowak, I.  Jarczewski, A. 
Treść / Zawartość
Warianty tytułu
Języki publikacji EN
Abstrakty
EN Unexpectedly the reaction of deprotonation of carbon acids with phosphazene bases occurred very slowly. The kinetic study of the proton transfer reactions between C-acids of the series of nitroalkanes with increasing bulk of R = H, Me, Et, i-Pr substituents as 4-nitrophenylnitromethane (1), 1-nitro-1-(4-nitrophenyl)ethane (2), 1-nitro-1-(4-nitrophenyl) propane (3), 2-methyl-1-nitro-1-(4-nitrophenyl)propane (4) and the tert-butylimino-tris(dimethylamino)phosphorane (5) named P1-t-Bu phosphazene is elaborated. The reactions have been studied in THF under pseudo-first-order conditions. The product of the proton transfer reactionwith P1-t-Bu in THF appeared to be associated into ion pairs. The equilibrium constants range from >100000 to 11.8 decreasing along with growing bulk of alkyl substituent in the reacting C-acid. The second order rate constants (k2H) are rapidly declining: 9360, 2.31, 0.66, 0.09 dm3 mol–1 s–1for 1, 2, 3, and4 respectively, and could not be accounted for the small values of the enthalpies of activation HH = 6.1, 18.0, 20.7 and 11.1 kJ mol–1. The reactions show negative and relatively large values of the entropies of activation SH = –149.7, –176.5, –178.7, –227.8 J mol–1 deg–1. The primary deuterium kinetic isotope effects are large showing tendency of reverse relation towards steric hindrance of the reacting C-acids, kH/kD = 15.8, 13.6, 13.2 for 1,2, and 3, respectively. The results have been discussed in terms of the influence of steric effects brought by the bulk of alkyl substituents in the C-acid and the base on formation of the transition state. Also the influence of traces of residual water present in the reaction system has been taken into consideration.
Słowa kluczowe
EN proton transfer   C-acids   phosphazene   rate constants   kinetic isotope effects  
Wydawca Polskie Towarzystwo Chemiczne
Czasopismo Polish Journal of Chemistry
Rocznik 2006
Tom Vol. 80, nr 12
Strony 2017--2029
Opis fizyczny Bibliogr. 33 poz., rys.
Twórcy
autor Wisłocka, I.
autor Nowak, I.
autor Jarczewski, A.
  • Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznan, Poland
Bibliografia
1. Schwesinger R., Angew. Chem., 105, 1420 (1994).
2. Wisłocka Ż., Nowak I. and Jarczewski A., J. Mol. Struct., in press.
3. Schroeder G., Łęska B., Jarczewski A., Nowak-Wydra B. and Brzezinski B., J. Mol. Struct., 344, 77 (1995).
4. Schwesinger R., Chimia, 39, 269 (1985).
5. Grześkowiak L, Gałęzowski W. and Jarczewski A., Can. J. Chem., 79, 1128 (2001).
6. Grześkowiak L, Gałęzowski W. and Jarczewski A., J. Chem. Soc., Perkin Trans. 2, 1607 (1998).
7. Bordwell F.G. and Fried H.E., Tetrahedron Lett., 1121 (1977).
8. Bordwell F.G., Bartmess J.E. and Hautala J.A., J. Org. Chem., 43, 3107 (1978).
9. Gałęzowski W. and Jarczewski A., Can J. Chem., 68, 2242 (1990).
10. Lewis E.S. and Funderburk L.H., J. Am. Chem. Soc., 89, 2322 (1967).
11. Jarczewski A. and Hubbard C.D., J. Mol. Struct., 649, 287 (2003).
12. Schwesinger R., Nachr. Chem. Tech. Lab., 38, 1214 (1990).
13. Leffek K.T., Pruszynski P. and Thanapaalasingham K., Can. J. Chem., 61, 590 (1989).
14. Schwesinger R., Willaredt J., Schlemper H., Keller M., Schmitt D. and Fritz H., Chem. Ber., 127, 2435 (1994).
15. Minksztym K. and Jarczewski A., J. Mol. Struct., 631, 203 (2003).
16. Gałązowski W. and Jarczewski A., Acta Chim. Hung., 127, 679 (1990).
17. Kresge A.J. and Powell M.F., J. Am. Chem. Soc., 103, 201 (1981).
18. Caldin E.F., Mateo S. and Warrick P, J. Am. Chem. Soc., 103, 202 (1981).
19. Rogne O., Acta Chem. Scand., Ser. A, 559 (1978).
20. Gałęzowski W. and Jarczewski A., Can. J. Chem., 70, 935 (1992).
21. Grześkowiak L, Gałęzowski W. and Jarczewski A., Can. J. Chem., 79, 1128 (2001).
22. Wisłocka Ż., Nowak I. and Jarczewski A., J. Mol. Struct. (submitted).
23. Stańczyk-Dunaj M., Gałęzowski W. and Jarczewski A., Can. J. Chem., 80, 1259 (2002).
24. Gałęzowski W. and Jarczewski A., J. Chem. Soc. Perkin Trans. II, 1647 (1989).
25. Gałęzowski W., Stańczyk-Dunaj M., Grześkowiak I. and Jarczewski A., J. Chem. Soc. Perkin Trans. 2, 2647(1996).
26. Nowak L, PhD Thesis (2001) University of A. Mickiewicz, Poznań, Poland, pp. 121, (in Polish).
27. Benesi H.A. and Hildebrand J.H., J. Am. Chem. Soc., 71, 2703 (1949).
28. Bell R.P., The Proton in Chemistry, Chapman and Hali, London, 2nd edn., ch. 7, 10, 12 (1973).
29. Terrier F., Xiao L., Farrell P.G. and Moscowitz D., J. Chem. Soc., Perkin Trans. 2, 1259 (1992) and refs therein.
30. Pruszynski P. and Jarczewski A., J. Chem. Soc. Perkin Trans. 11,1111 (1986).
31. Chem Files, " Strong and Hindered Bases in Organie Synthesis", Fluka, Vol. 3, No. l (2004).
32. Uvasol®, „Solvents and Auxiliaries for Spectroscopy", E. Merck, p. 98, (1980).
33. Caldin E.F., Jarczewski A. and Leffek K.T., Trans. Faraday Soc., 67, 110 (1971).
Kolekcja BazTech
Identyfikator YADDA bwmeta1.element.baztech-article-BUJ5-0005-0041
Identyfikatory