title: The synthesis of 1,2-bis(1,5,9-triazacyclododecyl)ethane: a showcase for the importance of the linker length within bis(alkylating) reagents.
abstract: The synthesis of 1,2-bis(1,5,9-triazacyclododecyl)ethane (1) showcases how different bis(alkylating) reagents change the reaction from an intra- to an intermolecular pathway. The isolation of the intermediate hexahydro-3a,6a-ethano-1H,4H,7H,9bH-9a-aza-3a,6a-diazoniaphenalene-3a,6a-diium (2) explained why initially the synthesis of 1 was not possible. Both isomers of 2 were found in solution. DFT calculations revealed that isomer 2a is 4.6 kcal/mol lower in energy than 2b. Synthesis of 1 was finally achieved by using oxalyl chloride.
authors.affiliation: University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Medina-Molner
authors.forename: Olivier
authors.initials: O
authors.lastname: Blacque
authors.forename: Bernhard
authors.initials: B
authors.lastname: Spingler
mesh_terms: D000478:Alkylation; D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004980:Ethane / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: C524837:1,2-bis(1,5,9-triazacyclododecyl)ethane; D001372:Aza Compounds; D003432:Cross-Linking Reagents; D004980:Ethane