title: Modular synthesis of cyclic cis- and trans-1,2-diamine derivatives.
abstract: Structurally diverse carbocycles with two vicinal nitrogen-substituents were prepared in expedient three-component reactions from simple amines, aldehydes, and nitroalkenes. trans,trans-6-Nitrocyclohex-2-enyl amines were obtained in a one-pot domino reaction involving condensation, tautomerisation, conjugate addition, and nitro-Mannich cyclisation. Upon employment of less nucleophilic carboxamides, a concerted Diels-Alder cycloaddition mechanism operated to give the corresponding cis,trans-nitrocyclohexenyl amides. Both types of substituted carbocycles offer ample opportunities for chemical manipulations at the core and periphery. Ring oxidation with MnO2 affords substituted nitroarenes. Reduction with Zn/HCl provides access to various trans- and cis-diaminocyclohexenes, respectively, in a straight-forward manner. With enantiopure secondary amines, a two-step synthesis of chiral nitrocyclohexadienes was developed (82-94% ee).
authors.affiliation: Department of Chemistry, University of Cologne, Germany.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Weber
authors.forename: Josef
authors.initials: J
authors.lastname: Schachtner
authors.forename: Robert
authors.initials: R
authors.lastname: Fichtler
authors.forename: Timo M
authors.initials: TM
authors.lastname: Leermann
authors.forename: Jörg M
authors.initials: JM
authors.lastname: Neudörfl
authors.forename: Axel
authors.initials: A
authors.lastname: Jacobi von Wangelin