Stereospecific synthesis of alkyl-substituted vicinal diamines from the mother diamine: overcoming the "intrinsic barrier" to the diaza-Cope rearrangement reaction.
Addition of isobutyraldehyde to 1,2-bis(2-hydroxyphenyl)-1,2-diaminoethane (mother diamine) cleanly gives a stable, fused imidazolidine-dihydro-1,3-oxazine ring complex. However, vigorous heating of the fused ring complex gives the diaza-Cope rearrangement product with excellent yield and stereoselectivity. A variety of alkyl aldehydes have been used to make corresponding alkyl diamines with excellent yield and stereospecificity. DFT computation shows that the intrinsic barrier for the rearrangement involving alkyl imines is about 7.9 kcal/mol greater than that involving aryl imines.
Kim
Hyunwoo
H
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6 Canada.
Staikova
Mima
M
Lough
Alan J
AJ
Chin
Jik
J
D000447:Aldehydes / Q000737:chemistry; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D003959:Diamines / Q000138:chemical synthesis* / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry*; D007097:Imines / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism; D013267:Stilbenes / Q000737:chemistry*
C534973:1,2-bis(2-hydroxyphenyl)-1,2-diaminoethane; D000447:Aldehydes; D003959:Diamines; D005029:Ethylenediamines; D007097:Imines; D013267:Stilbenes; C017439:isobutyraldehyde