A DFT Study on the Mechanism of the Annulation Reaction of Trichloronitroethylene with Aniline in the Synthesis of Quinoxalinone-N-oxides

Abstract

The new annulation reaction of trichloronitroethylene with aniline results in the formation of a quinoxalinone-N-oxide derivative. The mechanism of this one-pot annulation reaction between trichloronitroethylene (TCNiE) and anilines has been extensively investigated with B3LYP/6-31+G** methodology. Five different paths (1-5) were proposed and modeled by using this method. These paths were compared in terms of the activation energies of their rate-determining steps and in regard to the experimental findings. Paths 3 and 5, proceeding via four-membered heterocyclic rings, were found to be the most plausible paths with activation energies of 32 and 29 kcal/mol for the rate-determining steps, respectively. The effects of substituent, solvent, temperature, and computational method on these steps were also investigated. The results showed that path 5 is the most plausible mechanism for the annulation reaction of trichloronitroethylene with aniline.

Mechanisms of the Reaction between Polyhalogenated Nitrobutadienes and Electron-Deficient Anilines: Computational Modeling

“…The conversion of 4 to 5a proceeds through the 1,5-hydrogen shift of H14 to O6 via fairly flexible six-membered transition-state structure TS3 (−993.2 i ) having quite a small energy barrier of 2.55 kcal/mol. This small barrier is in agreement with the literature, since it is known that push–pull ethylenes of the same class as nitroenamine derivative 4 , having electron-donor and -acceptor groups at the CC double bond, exist in equilibrium with nitronic acid derivative 5a . , Nitroenamine 4 is 3.6 kcal/mol more stable than nitronic acid 5a . Bond distance C1–N13 is predicted as 1.344, 1.304, and 1.287 Å in structures 4 , TS3 , and 5a , respectively.…”

“…Geometrical parameters of reactants, products, transition states (TSs), and intermediates of all reaction steps were fully optimized with the hybrid density functional B3LYP , method by using the 6-31+G­(d,p) basis set unless otherwise stated, which is known to be reliable for estimating transition-state geometries of a variety of reactions. The B3LYP/6-31+G­(d,p) method was chosen as a compromise between accuracy and computational cost based on our previous computational modeling study on the reaction between trichloronitroethylene with aniline . The Gaussian 09 program package was used for all calculations.…”

“…The B3LYP/6-31+G(d,p) method was chosen as a compromise between accuracy and computational cost based on our previous computational modeling study on the reaction between trichloronitroethylene with aniline. 9 The Gaussian 09 12 program package was used for all calculations.…”

“…Recently, the annulation reaction of trichloronitroethylene 14 with aniline (Scheme 5) was theoretically modeled by our group. 9 Continuing our computational studies, we hope to present more detailed information about the chemistry of halonitroalkenes and their reactions with aniline derivatives.…”

Highly Efficient Synthesis of Quinoxalinone-N-oxide via Tandem Nitrosation/Aerobic Oxidative C–N Bond Formation

“…Quinoxalinone derivatives, including 3,4-dihydroquinoxalinone, show important biological and pharmacological properties and are widely used in material sciences. , Therefore a number of synthetic methods have been reported to date. , We hypothesized that quinoxalinone- N -oxides could be used as intermediates for their preparation . In particular, the CN group at the C2 position of 3 could be substituted by a variety of nucleophiles, readily enabling the derivatization.…”