title: Chiral Heteroditopic Baskets Designed from Triazolated Calixarenes and Short Peptides.
abstract: Cone calix[4]arenes and calix[6]arenes bearing two, three, and four short peptide units each having two chiral carbon atoms were prepared. The syntheses were performed by using an efficient modular approach that includes the Ugi preparation of the azido-peptide followed by its reactions with the propargylated calixarenes under CuAAC (Cu(I) -catalyzed azide-alkyne cycloaddition) conditions. The three novel multitopic hosts were probed for their ability to bind metal ions by UV titration, and showed the highest complexation efficiency towards copper(II) and lead(II). These two cations possessed quite different complexation modes with copper(II) bound predominantly by multiple-triazole sites, in contrast to lead(II), which is stabilized mainly by multiple interactions with amide groups of the peptide units. Circular dichroism data for the free chiral hosts, their equimolar mixtures with copper(II) perchlorate and lead(II) perchlorate, and for tertiary mixtures of all three compounds showed the formation of mono- and binuclear complexes, or a switching behavior, depending on the structure of the host and the addition order of the cations.
authors.affiliation: Department of Chemistry, M. V. Lomonosov Moscow State University, Lenin's Hills 1, 119991, Moscow, Russia.
authors.forename: Alexander
authors.identifier: http://orcid.org/0000-0003-0146-765X
authors.initials: A
authors.lastname: Gorbunov
authors.affiliation: Department of Chemistry, M. V. Lomonosov Moscow State University, Lenin's Hills 1, 119991, Moscow, Russia.
authors.forename: Nadezhda
authors.identifier: http://orcid.org/0000-0002-6211-608X
authors.initials: N
authors.lastname: Sokolova
authors.affiliation: Department of Chemistry, M. V. Lomonosov Moscow State University, Lenin's Hills 1, 119991, Moscow, Russia.
authors.forename: Elena
authors.identifier: http://orcid.org/0000-0002-9761-7757
authors.initials: E
authors.lastname: Kudryashova
authors.affiliation: Department of Chemistry, M. V. Lomonosov Moscow State University, Lenin's Hills 1, 119991, Moscow, Russia.
authors.forename: Valentine
authors.initials: V
authors.lastname: Nenajdenko
authors.affiliation: Department of Chemistry, M. V. Lomonosov Moscow State University, Lenin's Hills 1, 119991, Moscow, Russia.
authors.forename: Vladimir
authors.identifier: http://orcid.org/0000-0003-4473-1107
authors.initials: V
authors.lastname: Kovalev
authors.affiliation: Department of Chemistry, M. V. Lomonosov Moscow State University, Lenin's Hills 1, 119991, Moscow, Russia. vatsouro@petrol.chem.msu.ru.
authors.forename: Ivan
authors.identifier: http://orcid.org/0000-0001-8629-1897
authors.initials: I
authors.lastname: Vatsouro
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001386:Azides / Q000737:chemistry*; D047250:Calixarenes / Q000737:chemistry*; D002384:Catalysis; D002412:Cations / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D014230:Triazoles / Q000737:chemistry*
chemical_list: D000480:Alkynes; D001386:Azides; D002412:Cations; D010455:Peptides; D014230:Triazoles; D047250:Calixarenes; D003300:Copper
keywords: calixarenes; circular dichroism; click chemistry; heterometallic complexes; nitrogen heterocycles