Search results for "combinatorial"

Single Heteroatom Fine-Tuning of the Emissive Properties in Organoboron Complexes with 7-(Azaheteroaryl)indole Systems

2016

The application of organoboron compounds as light-absorbing or light-emitting species in areas as relevant as organic electronics or biomedicine has motivated the search for new materials which contribute to the progress of those applications. This article reports the synthesis of four-coordinate boron complexes based on the unexplored 7-(azaheteroaryl)indole ligands. An easy synthetic approach has enabled the fine-tuning of the electronic structure of the organoboron species by modifying a heteroaromatic component in the conjugated system. Furthermore, a comprehensive characterization by X-ray diffraction, absorption and emission spectroscopy, both in solution and in the solid state, cycli…

Synthesis of silacyclopent-2-en-4-ols via intramolecular [2 + 2] photocycloaddition of benzoyl(allyl)silanes

2019

Organosilicon compounds are versatile units with a wide range of uses from medicinal chemistry to the field of organic electronics. An unprecedented method for the synthesis of novel diaryl-substituted silacyclopentenols via blue-light promoted intramolecular [2 + 2] photocycloaddition of acyl silanes is herein disclosed. Additionally, the present findings demonstrate the influence of the olefin substituents in controlling the regioselectivity of the intramolecular Paterno–Buchi reaction, providing silacycles different from previously reported ones. The high degree of functionalization of these compounds makes them attractive precursors to other synthetically challenging silacyclopentanes.

Synthesis of Heteroaromatics via Rearrangement Reactions

2010

Metal complexes of oxadiazole ligands: An overview

2019

Oxadizoles are heterocyclic ring systems that find application in different scientific disciplines, from medicinal chemistry to optoelectronics. Coordination with metals (especially the transition ones) proved to enhance the intrinsic characteristics of these organic ligands and many metal complexes of oxadiazoles showed attractive characteristics for different research fields. In this review, we provide a general overview on different metal complexes and polymers containing oxadiazole moieties, reporting the principal synthetic approaches adopted for their preparation and showing the variety of applications they found in the last 40 years.

Synthesis and biological evaluation of structural variants of carbazoquinocin C

2003

Some new structural variants of the alkaloid carbazoquinocin C were synthesized in a few steps with good to excellent yields. The key step comprises a cyclisation reaction of appropriate 2-vinylindoles with oxalyl chloride. The carbazole-3,4-quinones are able to trap oxygen-centred radicals. In some biological/biochemical assays some of these compounds exhibit extraordinary results including inhibition of cyclooxygenase-1 and 5-lipoxygenase in the μM-range. Moreover some of the carbazoquinocin C-variants inhibit significant oxidative damage of cellular DNA in nM-range.

Magneli-type tungsten oxide nanorods as catalysts for the selective oxidation of organic sulfides

2021

Selective oxidation of thioethers is an important reaction to obtain sulfoxides as synthetic intermediates for applications in the chemical industry, medicinal chemistry and biology or the destruction of warfare agents. The reduced Magneli-type tungsten oxide WO3−x possesses a unique oxidase-like activity which facilitates the oxidation of thioethers to the corresponding sulfoxides. More than 90% of the model system methylphenylsulfide could be converted to the sulfoxide with a selectivity of 98% at room temperature within 30 minutes, whereas oxidation to the corresponding sulfone was on a time scale of days. The concentration of the catalyst had a significant impact on the reaction rate. R…

Selective Recognition of Phenazine by 2,6‐Dibutoxylnaphthalene‐Based Tetralactam Macrocycle

2019

A 2,6‐dibutoxylnaphthalene‐based tetralactam macrocycle was designed and synthesized. This macrocycle shows highly selective recognition to phenazine ‐‐ a well‐known secondary metabolite in bacteria and an emerging disinfection byproduct in drinking water. In contrast, the macrocycle shows no binding to the structurally similar dibenzo‐1,4‐dioxin. It was revealed that hydrogen bonding, π‐π and σ‐π interactions are the major driving forces between phenazine and the new tetralactam macrocycle. A perfect complementarity in electrostatic potential surfaces may explain the high selectivity. In addition, the macrocycle shows fluorescent response to phenazine, demonstrating its potential in fluore…

In Vitro Evaluation of the Squaramide-Conjugated Fibroblast Activation Protein Inhibitor-Based Agents AAZTA5.SA.FAPi and DOTA.SA.FAPi

2021

Recently, the first squaramide-(SA) containing FAP inhibitor-derived radiotracers were introduced. DATA5m.SA.FAPi and DOTA.SA.FAPi with their non-radioactive complexes showed high affinity and selectivity for FAP. After a successful preclinical study with [68Ga]Ga-DOTA.SA.FAPi, the first patient studies were realized for both compounds. Here, we present a new squaramide-containing compound targeting FAP, based on the AAZTA5 chelator 1,4-bis-(carboxylmethyl)-6-[bis-(carboxymethyl)-amino-6-pentanoic-acid]-perhydro-1,4-diazepine. For this molecule (AAZTA5.SA.FAPi), complexation with radionuclides such as gallium-68, scandium-44, and lutetium-177 was investigated, and the in vitro properties of…

Peptidomimetics – An infinite reservoir of metal binding motifs in metabolically stable and biologically active molecules

2020

The involvement of metal ions in interactions with therapeutic peptides is inevitable. They are one of the factors able to fine-tune the biological properties of antimicrobial peptides, a promising group of drugs with one large drawback - a problematic metabolic stability. Appropriately chosen, proteolytically stable peptidomimetics seem to be a reasonable solution of the problem, and the use of D-, β-, γ-amino acids, unnatural amino acids, azapeptides, peptoids, cyclopeptides and dehydropeptides is an infinite reservoir of metal binding motifs in metabolically stable, well-designed, biologically active molecules. Below, their specific structural features, metal-chelating abilities and anti…

Molecular Classification of Pesticides Including Persistent Organic Pollutants, Phenylurea and Sulphonylurea Herbicides

2014

Pesticide residues in wine were analyzed by liquid chromatography–tandem mass spectrometry. Retentions are modelled by structure–property relationships. Bioplastic evolution is an evolutionary perspective conjugating effect of acquired characters and evolutionary indeterminacy–morphological determination–natural selection principles; its application to design co-ordination index barely improves correlations. Fractal dimensions and partition coefficient differentiate pesticides. Classification algorithms are based on information entropy and its production. Pesticides allow a structural classification by nonplanarity, and number of O, S, N and Cl atoms and cycles; different behaviours depend …