105786-83-2Relevant academic research and scientific papers
Diazepinones from Sydnones and Isopropylidenecyclobutenone. Extension of the Frontier Molecular Orbital Model for Sydnone Cycloadditions
Mais, Franz-Josef,Dickopp, Heinz,Middelhauve, Birgit,Martin, Hans-Dieter,Mootz, Dietrich,Steigel, Alois
, p. 275 - 284 (2007/10/02)
On heating the sydnones 1a-h with isopropylidenecyclobutenone (2) in refluxing toluene dihydrodiazepin-5-ones (3a-h) are obtained in the case of N-phenyl- and dialkylsydnones.The N-alkyl-C-hydrogensydnones, however, yield two regioisomeric products, the dihydrodiazepin-5-ones 3d,e as well as the corresponding diazepin-4-ones 4d,e.The frontier molecular orbital model, as applied to sydnones, is critically examined.Extension of the simple model to the calculation of selected encounter complexes is presented.In this way not only the preferred formation of diazepin-5-ones (3) is correctly predicted but the ratio of 3:4 is also satisfactorily reproduced.X-ray diffraction has been used to determine the structure of 4d which is between a boat and a chair and shows a very short NN single bond.
