title: Enantioselective cyclization of racemic supramolecular polymers.
abstract: Homochiral hydrogen-bonded cyclic assemblies are formed in dilute solutions of racemic supramolecular polymers based on the quadruple hydrogen bonding 2-ureido-4[1H]-pyrimidinone unit, as observed by 1H NMR and SEC experiments. Preorganization of the monomers and the combined binding strength of the eight hydrogen bonds result in a very high stability of the cyclic aggregates with pronounced selectivity between homochiral and heterochiral cyclic species, usually only observed in crystalline or liquid crystalline phases.
authors.affiliation: Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: A Tessa
authors.initials: AT
authors.lastname: ten Cate
authors.forename: Patricia Y W
authors.initials: PY
authors.lastname: Dankers
authors.forename: Huub
authors.initials: H
authors.lastname: Kooijman
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Spek
authors.forename: Rint P
authors.initials: RP
authors.lastname: Sijbesma
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
mesh_terms: D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D011744:Pyrimidinones / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011108:Polymers; D011744:Pyrimidinones