RESUMEN
Gold nanoparticles (Au NPs) with tailor-made structures and properties are highly desirable for applications in catalysis and sensing. In this context, surface modifications of Au NPs are of particular relevance. Herein, we present a sequential surface modification of Au NPs with Ag(I) coordination complexes, which can be converted into Ag(0)-doped Au NPs by simple ligand-exchange reaction. The key innovative element of this surface modification is a multifunctional bioxazoline-based ligand that brings coordinated Ag(I) into close proximity to the particle surface.
RESUMEN
Taking advantage of Rh(III)-catalyzed C-H activation reactions, we have developed a mild, short, and efficient method for the synthesis of bench-stable 3-isoquinolone MIDA boronates. The reaction is practical and scalable. The product formed has been applied in the Suzuki-Miyaura reaction with high efficiency. This strategy has also been successfully expanded to the synthesis of MIDA boronate functionalized heterocycles such as isoquinoline, pyrrole, and indole.
RESUMEN
C(6)Br(six) & drugs! C(6)Br(6) can be used as the cooxidant/catalyst modifier for the [Rh(III)Cp*]-catalyzed (Cp*=C(5)Me(5)) dehydrogenative cross-coupling of benzamides with simple benzene derivatives (see scheme, DG=directing group). Similarly, heterocycles can be coupled and druglike structures formed. Mechanistic studies suggest a unique and multiple role of the Cu(OAc)(2)/C(6)Br(6) system and a nonchelate-assisted C-H activation as the rate-determing step.
Asunto(s)
Alquenos/química , Bromobencenos/química , Rodio/química , Benzamidas/química , Carbono/química , Catálisis , Hidrógeno/químicaRESUMEN
Herein, a rhodium(III)-catalyzed oxidative C-H activation of simple arylphosphonates and phosphonamides with subsequent coupling with alkenes (olefination), internal alkynes (hydroarylation and oxidative cyclization), or simple arenes to give access to diverse P-containing functional frameworks is reported.
Asunto(s)
Alquenos/síntesis química , Organofosfonatos/química , Rodio/química , Alquenos/química , Alquinos/química , Catálisis , Ciclización , Estructura Molecular , Oxidación-ReducciónRESUMEN
Five compounds displaying an unprecedented binding mode of chloroquine to ferrocene through the bridging of the cyclopentadienyl rings were studied alongside their monosubstituted ferrocene analogues and organic fragments. The antiplasmodial activity was evaluated against strains of the malaria parasite (Plasmodium falciparum). While the chloroquine-bridged ferrocenyl derivatives were less active than their five monosubstituted ferrocenyl analogues, they retained activity in the drug-resistant strains. The biological and physical properties were correlated to antiplasmodial activity. Intramolecular hydrogen bonding was associated with increased antiplasmodial action, but it is not the determining factor. Instead, balance between lipophilicity and hydrophilicity had a greater influence. It was found that calculated partition coefficient (log P) values of 4.5-5.0 and topological polar surfaces area (tPSA) values of â¼26.0 Å(2) give the best balance. The particular conformation, compact size, and lipophilicity/hydrophilicity balance observed in the bridged compounds provide them with the structural characteristics needed to escape the mechanisms responsible for resistance.
Asunto(s)
Aminoquinolinas/química , Antimaláricos/química , Cloroquina/análogos & derivados , Cloroquina/química , Compuestos Ferrosos/química , Aminoquinolinas/síntesis química , Aminoquinolinas/farmacología , Antimaláricos/síntesis química , Antimaláricos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Cloroquina/síntesis química , Cloroquina/farmacología , Cristalografía por Rayos X , Resistencia a Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Compuestos Ferrosos/síntesis química , Compuestos Ferrosos/farmacología , Hemina/química , Humanos , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Metalocenos , Modelos Moleculares , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Plasmodium falciparum , Relación Estructura-ActividadRESUMEN
A Rh catalyzed, no-chelate-assisted C-H activation/oxidative olefination reaction of bromoarenes has been discovered, in which the latter ones seem to act as a substrate, terminal oxidant, and catalyst modifier.