title: The assembly of macrocyclic bis- and tetra-beta-lactams with embedded platinum or palladium square-planar centers.
abstract: The synthesis, isolation, and full characterization of different types of stable, metal-assembled macrocyclic beta-lactams are reported. By using adequately functionalized bis-beta-lactams with defined stereochemistry as building blocks, a series of mono- and bimetallic Pd and Pt macrocycles has been prepared in good to quantitative yields. These novel structures combine the beta-lactam moiety with transition-metal fragments with cis-square-planar geometry and constitute a new class of metal-assembled cavities involving molecules with biological relevance as building blocks. By combining the adequate ligands, metallic fragments, and tuning the reaction conditions, different mono- and bimetallic macrocyclic beta-lactam cavities can be selectively obtained. Macrocycles with Pt-ethynyl groups are suitable to form host-silver triflate guest complexes in a tweezer fashion.
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, 28040-Madrid, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Pellico
authors.forename: Mar
authors.initials: M
authors.lastname: Gómez-Gallego
authors.forename: Pedro
authors.initials: P
authors.lastname: Ramírez-López
authors.forename: María José
authors.initials: MJ
authors.lastname: Mancheño
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Sierra
authors.forename: M Rosario
authors.initials: MR
authors.lastname: Torres