ORGN 573 |
| It has been reported that the Darbeau-White-Gibble Reaction utilizes deaminatively generated N-nitrosoamides in various nitriles to modestly produce an alternative method for the preparation of unsymmetrical diacylamines (DAAs). In an effort to systematically examine this cascade of reactions, Darbeau et al. peformed a series of experiments to gain insight into the reaction's mechanism as well as the limitations of its methodology. The molecules investigated were the pivalate ion, the N-benzylacetonitrilium ion (from the 4-R-benzonitrile solvents where R=NH2, Me2N, MeO, Me, H, F, and CF3), the (Z)- and (E)-ethanimidic anhydrides and N-acetyl-N-pivaloyl-4-R-benzylamine (where R=NH2, Me2N, MeO, Me, H, F, and CF3). Model calculations at the B3LYP/6-31++G (d,p) level were performed to probe the potential energy hypersurface to provide insight into the reaction mechanism. Optimization of these structures and frequency calculation were done using the Gaussian98 and Gaussian03 suites. Several critical points characterized by harmonic vibrational frequencies and the surface verified by intrinsic reaction coordinate (IRC) calculations were found. In tandem with the experimental results, these calculations aided us into understanding the reaction mechanism of the Darbeau-White-Gibble Reaction. |
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Asymmetric Reactions, Heterocycles, Aromatics, Combinatorial, and Physical Organic Chemistry
8:00 PM-10:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- Hall A, Poster
Division of Organic Chemistry |