ASYMMETRIC NITROGEN-41 STEREOCHEMISTRY OF BICYCLIC 1,2-CIS-DIAZIRIDINES

Article abstract of DOI:10.1016/S0040-4020(01)91378-X

The twisting of 5- and 6-membered rings in bicyclic cis-diaziridines-1,5-diazabicyclo(3.1.0)hexanes 12-17 and 1,6-diazabicyclo(4.1.0)heptane 18-is a rapid process in the time scale of ¹H- and ¹³C-NMR even at -80 deg C.According to the ¹H- and ¹³C-NMR spectra, 1,5-diazabicyclo(3.1.0)hexanes 12, 13, 15a,b and 16a, b do, exist mostly in the boat form; only the introduction of endo substituents into position 3 or 6 leads to the population of the chair, as is the case with 14 and 17. 2,4-Dialkyl substituted 1,5-diaza- and 1,3,5-triazabicyclo(3.1.0)hexanes are formed via a transition cyclization state similar in its geometry to the initial chair-shaped N-chlorodi(tri)azanes.