title: Stereospecific synthesis of C2 symmetric diamines from the mother diamine by resonance-assisted hydrogen-bond directed diaza-Cope rearrangement.
abstract: Sixteen diphenylethylenediamine analogues including those with electron donating, electron withdrawing, and sterically bulky substituents have been prepared in good overall yields (70-90%) and in enantiomerically pure form (>99% ee) by diaza-Cope rearrangement reaction. A single chiral mother diamine, ((R,R)-1,2-bis-(2-hydroxyphenyl)-1,2-diaminoethane), is reacted with appropriate aldehydes to form the initial diimines that rearrange to give all the product diimines in the (S,S) form. The daughter diamines are obtained by hydrolysis of the product diimines. Density functional theory computation shows that resonance-assisted hydrogen-bond is the main driving force behind all the rearrangement reactions. Chiral high performance liquid chromatography and circular dichroism spectroscopy show that the highly stereospecific rearrangement reactions take place with apparent inversion of stereochemistry.
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
authors.forename: Hyunwoo
authors.initials: H
authors.lastname: Kim
authors.forename: Yen
authors.initials: Y
authors.lastname: Nguyen
authors.forename: Cindy Pai-Hui
authors.initials: CP
authors.lastname: Yen
authors.forename: Leonid
authors.initials: L
authors.lastname: Chagal
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Lough
authors.forename: B Moon
authors.initials: BM
authors.lastname: Kim
authors.forename: Jik
authors.initials: J
authors.lastname: Chin
mesh_terms: D001372:Aza Compounds / Q000737:chemistry; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D005029:Ethylenediamines / Q000138:chemical synthesis*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D001372:Aza Compounds; D005029:Ethylenediamines; C518332:diphenylethylenediamine