29768-31-8Relevant academic research and scientific papers
Stereoselective (exo-specific) synthesis, dynamic 1H NMR and quantum chemical conformational and configurational analysis of norbornene-aziridine-E- imidoyl system
Dabbagh, Hossein A.,Chermahini, Alireza Najafi
, p. 339 - 348 (2012)
Stereoselective (exo-specific) synthesis, dynamic 1H NMR and computational analysis of exo-N0-{3-azatricyclo[3.2.1.0.2,4]oct-3-yl) mesithyloxy)methylene}-1-benzensulfunamide (3) were investigated. Aziridine nitrogen inversion gives rise to two sets of configurations where the N-substituent is Syn (S) or Anti (A) to C7 of the norbornyl ring. At lower temperature, the proton signals of aziridine exo-E-3 decoalesces to show two syn conformers and one anti conformer (exo-E-31S = exo-E-32S = exo-E-33A) with ratio of 60:20:20, respectively. Experimentally, the Gibbs free energy of activations [DG= (kcal/mol) ± 0.08] were calculated 11.96, 12.45 for 3 isomerizations. The standard Gibbs free energy (DGo kcal/mol) 0.174, 0, 0.174, and 0.298 at 213 K and energy minimum 6.64, 4.77 and 1.78 were calculated for 31S = 32S, 3 2S = 33A, 31S = 33A isomerizations, respectively. The enthalpy (δH=, kcal/mol) and entropy (δS=, cal mol-1 K-1) of activation for the nitrogen inversion of aziridine of 3 were calculated 11.2 and-0.80, respectively.
