title: Regioselective N-functionalization of tetraazacycloalkanes.
abstract: [reaction: see text] Bisaminal type compounds obtained by condensation of pyruvic aldehyde with the suitable open-chain tetraamine followed by cyclization with either dibromoethane or dibromopropane can be regioselectively quaternized by a wide range of alkylating agents. Removal of the bisaminal bridge yields the monosubstituted tetraazamacrocycle or bismacrocycle. Further functionalization allows the preparation of bifunctional ligands or trisubstituted macrocycles. The structure of six compounds was solved by X-ray diffraction, and the unexpected results are rationalized according to the molecular modeling calculations.
authors.affiliation: Université de Bourgogne, Laboratoire d'Ingénierie Moléculaire pour la Séparation et les Applications des Gaz, LIMSAG UMR 5633, Faculté des Sciences Gabriel, 6 boulevard Gabriel, 21100 Dijon, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Boschetti
authors.forename: Franck
authors.initials: F
authors.lastname: Denat
authors.forename: Enrique
authors.initials: E
authors.lastname: Espinosa
authors.forename: Alain
authors.initials: A
authors.lastname: Tabard
authors.forename: Yves
authors.initials: Y
authors.lastname: Dory
authors.forename: Roger
authors.initials: R
authors.lastname: Guilard