Metal-Organic Framework with Dual Active Sites in Engineered Mesopores for Bioinspired Synergistic Catalysis.

Here we report the design of an enzyme-inspired metal-organic framework (MOF), 1-OTf-Ir, by installing strong Lewis acid and photoredox sites in engineered mesopores. Al-MOF (1), with mixed 2,2'-bipyridyl-5,5-dicarboxylate (dcbpy) and 1,4-benzenediacrylate (pdac) ligands, was oxidized with ozone and then triflated to generate strongly Lewis acidic Al-OTf sites in the mesopores, followed by the installation of [Ir(ppy)2(dcbpy)]+ (ppy = 2-phenylpyridine) sites to afford 1-OTf-Ir with both Lewis acid and photoredox sites. 1-OTf-Ir effectively catalyzed reductive cross-coupling of N-hydroxyphthalimide esters or aryl bromomethyl ketones with vinyl- or alkynyl-azaarenes to afford new azaarene derivatives. 1-OTf-Ir enabled catalytic synthesis of anticholinergic drugs Pheniramine and Chlorpheniramine.

[Synthesis and combined H1-/H2 antagonist activity of mepyramine, pheniramine and cyclizine derivatives with cyanoguanidine, urea and nitroethenediamine partial structures]. / Synthese und kombinierte H1-/H2-antagonistische Aktivität von Mepyramin-, Pheniramin- und Cyclizin-Derivaten mit Cyanoguanidin-, Harnstoff- und Nitroethendiamin-Partialstrukturen.

Compounds with combined histamine H1- and H2-receptor antagonist activity were synthesized by connecting H1- and H2-receptor substructures via cyanoguanidine, urea, or nitroethenediamine moieties. Loss of the strongly basic side-chain nitrogen results in a decrease of H1-receptor activity compared to single reference compounds. At the guinea-pig right atrium (H2-receptor model) compounds with mepyramine or cyclizine structure are also less active than the single references tiotidine, ranitidine, or lamtidine. Nevertheless substances with a pheniramine like partial structure proved to be potent histamine H2-receptor antagonists at the atrium model (about 27 times more active than cimetidine).