57355-62-1Relevant academic research and scientific papers
The Synthesis of Indolizidine and Quinolizidine Ring Systems by Free Radical Cyclization of 4-Aza-6-methoxycarbonyl-5-hexenyl Radicals
Beckwith, Athelstan L. J.,Westwood, Steven W.
, p. 5269 - 5282 (2007/10/02)
The formation of bicyclic amines by the intramolecular cyclization of 4-aza-6-methoxycarbonyl-5-hexenyl radicals is described.The direct attachment of a nitrogen atom to the double bond changes the electronic nature of the alkene such that the cyclization is less efficient than the all carbon analogue or the other aza-substituted 5-hexenyl cyclizations.The reaction has been used in a short, convenient synthesis of a variety of indolizidines from methyl nicotinate.In addition, the cyclization was used as the key step in a short synthesis of (+/-)-epilupinine from methyl nicotinate.
Structure Sensitivity of the Marcus λ for Hydride Transfer between NAD+ Analogues
Kreevoy, Maurice M.,Ostovic, Drazen,Lee, In-Sook Han,Binder, David A.,King, Gary W.
, p. 524 - 530 (2007/10/02)
Thirty-five rate constants, kij, for transfer of hydride between various pyridinium, quinilinium, acridinium, and phenantridinium ions spanning a range of over 10E11 in their equilibrium constants Kij and over 10E6 in kij
Marcus Theory of Hydride Transfer from an Anionic reduced Deazaflavin to NAD+ Analogues
Lee, In-Sook Han,Ostovic, Drazen,Kreevoy, Maurice
, p. 3989 - 3993 (2007/10/02)
Eighteen rate constants, kij for hydride transfer from the conjugate base of 1,5-dihydro-3,10-dimethyl-5-diazaisoalloxazine to a variety of pyridinium, quinolinium, phenanthridinium, and acridinium ions have been determined. (All the oxidizing agents can be regarded as analogues of NAD+.) The kij values span 7 powers of 10 and the corresponding equilibrium constants, Kij, span more than 13 powers of 10.For reactions with ΔG0 near zero, the kij values are close to those given by modified Marcus theory (ref 10).However, with more negative ΔG0 values, the observed kij increase more strogly than the calculated values.Agreement can be produced by making the standard free energy of precursor complex formation, symbolized WT +- here, to indicate that it applies to reactants of opposite charge, a linear function of ΔG0, and treating the slope and interrcept of the linear relation as adjustable parameters.The best fit is obtained with WT+-(in kJ*mol-1)=-9.4+0.11ΔG0.An avarage discrepancy between calculated and observed ln kij values of 0.5 is achieved, which is a good as the overall fit achieved for hydride transfer from neutral NADH analogues to NAD+ analogues (ref 10).The form and the parameterization of Wf are shown to be a physically reasonable approximation for reactions with ΔG00.These results strengthen the conclusion (ref 10) that a wide range of hydride transfer rates can be quantitavely understood without introducing high-energy metastable intermediates (radicals and radical ions).
Hydride Transfer and Oxyanion Addition Equilibria of NAD+ Analogues
Ostovic, Drazen,Lee, In-Sook Han,Roberts, Roger M. G.,Kreevoy, Maurice M.
, p. 4206 - 4211 (2007/10/02)
Equilibrium constants, K, have been determined for the reduction of 10-methylacridinium ion by 15 N-heterocyclic hydride donors: acridine, quinoline, pyridine, and phenanthridine derivatives.The solvent was a mixture of 2-propanol and water in the ratio 4 : 1 by volume.Reduction potentials have been estimated for the corresponding cations in aqueous solution by assuming that the K's would be the same and accepting -361 mV as the reduction potential of the 3-(aminocarbonyl)-1-benzylpyridinium ion.These reduction potentials span 430 mV.Values of pKR have also been determined for six of the cations in the same solvent.For derivatives of the same ring system, -ΔlogK is approximately equal to ΔpKR, but a 4 log unit discrepancy appears when phenanthridine derivatives are compared with the 9-methylacridinium ion.
