Sterically Demanding Ethylenediamines and Polyamines for the Stabilization of Main Group Elements in Low Coordination Numbers
This thesis explores the reaction of primary amines with 1,2-dibromoethane and 1,3-dibromopropane as a one step synthesis of N,N"-disubstituted ethylenediamines, RNH- CH2CH2-NH-R, N,N"-disubstituted propanediamines, R-NH-CH2CH2CH2-NH-R and N-substituted azetidines RN[(CH2)3]. Unlike earlier approaches in the literature, this method circumvents the use of the highly toxic #-haloamines. The reaction can also be a convenient approach to N,N",N""-trisubstituted diethylenetriamines which form as byproducts in the synthesis of the ethylenediamines and are readily separated by distillation. The respective propylenetriamines were obtained in analogous fashion from 1,3-dibromopropane. The use of N,Nʼ,N”- trisubstituted triamines for the stabilization of low valent main group compounds was exemplified through the synthesis and structural characterization of a phosphenium salt. N,N'-disubstituted ethylenediamines, R-NH-CH2CH2-NH-R" bearing different substituents R are difficult to obtain and require multi-step protocols. This thesis describes their one step synthesis from aziridines and primary amines. The analogous 1,3-propandiamines were obtained from primary amines and azetidines. N-tert-Butylimidazol was obtained through thermolysis of 1,3-di-tertbutylimidazolium chloride and used as precursor for bis carbenes.