13C kinetic isotope effects and the mechanism of the uncatalyzed decarboxylation of orotic acid

Journal of the American Chemical Society

Volumn 122, Issue 14, 2000, Pages 3296-3300

  Singleton, Daniel A ^a,b,c   Merrigan, Steven R ^a,b,c   Kim, Bong J ^a,b,c   Beak, Peter ^a,b,c   Phillips, Linda M ^a,b,c   Lee, Jeehiun K ^a,b,c  

^a TEXAS A AND M UNIVERSITY   (United States)

^b UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN   (United States)

^c RUTGERS UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CARBON 13; OROTIC ACID;

ARTICLE; CATALYSIS; CHEMICAL BOND; CHEMICAL STRUCTURE; DECARBOXYLATION; ENZYME ACTIVITY; PROTON TRANSPORT; REACTION ANALYSIS;

EID: 0034639902     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja993392m     Document Type: Article

References (26)

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19. Bach, R. D.; Canepa, C. J. Am. Chem. Soc. 1997, 119, 11725. Becke3LYP/6-31+G* calculations were previously found to give a reasonably accurate prediction of the barrier for the orotate decarboxylation (see ret 13).
20. For calculating the entropy the frequency of the normal mode associated with the reaction coordinate was omitted, even when this frequency was real.
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24. (Scott, A. P.; Radom, L. J. Phys. Chem. 1996, 100, 16502.). Tunneling corrections
25. (Bell, R. P. The Tunnel Effect in Chemistry: Chapman & Hall: London, 1980; pp 60-63) were negligible.
26. 3). The predicted isotope effects for this decarboxylation are 1.001, 1.005, 1.007, 1.030, and 1.008 at C2, C4, C5, C6, and the carboxylate, respectively, which does not fit as well with the experimental values. Beak and Siegel (see ref 5) had previously ruled out decarboxylation of the carboxylate anion based on kinetic considerations.