Theoretical studies on the hydride transfer between 1-methyl-1,4-dihydronicotinamide and its corresponding pyridinium salt
✍ Scribed by Nicholas Bodor; Marcus E Brewster; James J Kaminski
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- French
- Weight
- 628 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0040-4020
No coin nor oath required. For personal study only.
✦ Synopsis
mO0 and AYl studies were perforad to investigate the degenerate hydride transfer reaction between 1-methyl-1,4-dihydronicotlnanide and the lmthylnicotlnamidc cation, a node1 system for a novel braln-targeted delivery system and for the ICAD' : RAW Interconversion. Four initial approach vectors were selected. These involved an endo orientation in which the carbaaoyl groups are xwlth respect to one another (cis &_-PC). an endo orientatlon with the carbamoyl groups fi (cls MS-sl), an exo conflguratlon with the carbamoyl groups syn (trans MS-s) and an exo configuration with the carbamoyl groups antf (trans liS-z). The cis NS-3approach generated the transition state with the lowst energy. The optimized structure indicated that a linear hydride transfer occurred. A more detailed study examined the cis Hs-~ approach from a 1001 separation to the transltlon state. The data Indicated the formation of an lntennediate induced dipole-charge complex which altered the trajectory of the two species. Closer approach yielded the transition state. The energy of activation for this reaction was calculated to be 30.7 kcal/nbl uslng the mO0 approximatlon and 9.3 keel/ml using the AM1 arthod. Finally, while the linear transition state was found to be the most stable conformation, bending of the C-H-C bond by f 300 only modestly increased (3-4 kcal/mol) the energy of the systm.