Search results for "combinatorial"
showing 10 items of 1208 documents
Anodische dehydrierende Cyaniminierung von Thioethern: eine einfache und nachhaltige Synthese von N ‐Cyansulfiliminen
2021
Direct Metal‐ and Reagent‐Free Sulfonylation of Phenols with Sodium Sulfinates by Electrosynthesis
2019
A novel electrochemical strategy for the synthesis of aryl sulfones by direct sulfonylation of phenols with sodium sulfinates has been developed. The C,S-coupling products are of particular interest for chemical synthesis, material sciences and pharmaceutical sciences. By using this metal- and reagent-free electrochemical method, aryl and diaryl sulfones can be obtained directly in good yields. The established one-step protocol is easy to perform, scalable, inherently safe, and enables a broad scope, which is not limited by quinoid-forming substrates.
Ultra-Low Catalyst Loading as a Concept in Economical and Sustainable Modern Chemistry: The Contribution of Ferrocenylpolyphosphane Ligands
2007
The challenge of sustainability in modern chemistry will be met with new technologies and processes provided significant progress is made in several key research areas, such as the expansion of chemistry from renewable feedstock, the design of environmentally benign chemicals and solvents, the minimization of depletive resources, and the development of high-performance catalysis. In this prospect, ligand chemistry is a pivotal science that links modern-organic,-inorganic, -organometallic, and -coordination chemistry through a vast number of valuable applications, precisely associated to catalysis. We review in this article our recent work on catalysis promoted by original ferrocenyl tetra-,…
Uncommon perspectives in palladium- and copper-catalysed arylation and heteroarylation of terminal alkynes following Heck or Sonogashira protocols: I…
2013
Abstract Conjugated alkynes are recurring building blocks in natural products and in a wide range of important compounds, such as pharmaceuticals, agrochemicals, or molecular materials. The palladium-catalysed cross-coupling reaction between the sp 2 -hybridized carbon atoms of aryl, heteroaryl, and vinyl halides with the sp -hybridized carbon atoms of terminal alkynes is one of the most important developments in the field of alkyne chemistry over the past 50 years. Room for improvement still exists in these important reactions of direct arylation of terminal alkynes. In this prospect, the present authors have developed several strategies aiming at improving the reactivity, the selectivity,…
Metal‐Free Twofold Electrochemical C−H Amination of Activated Arenes: Application to Medicinally Relevant Precursor Synthesis
2020
Abstract The efficient production of many medicinally or synthetically important starting materials suffers from wasteful or toxic precursors for the synthesis. In particular, the aromatic non‐protected primary amine function represents a versatile synthetic precursor, but its synthesis typically requires toxic oxidizing agents and transition metal catalysts. The twofold electrochemical amination of activated benzene derivatives via Zincke intermediates provides an alternative sustainable strategy for the formation of new C−N bonds of high synthetic value. As a proof of concept, we use our approach to generate a benzoxazinone scaffold that gained attention as a starting structure against ca…
Optimal selection of touristic packages based on user preferences during sports mega-events
2022
Sport mega-events, such as the Soccer World Cup or Olympic Games, attract many visitors from all over the world. Most of these visitors are also interested in, besides attending the sports events, visiting the host nation and the neighboring countries. In this paper, we focus on the upcoming FIFA World Cup Qatar 2022. As per the schedule of the tournament, a national team can play 7 matches at most. Therefore, a supporter will have six short breaks (of three to five days) between consecutive matches in addition to two longer ones, immediately before and after the tournament, during which they can plan some touris- tic trips. We study the problem faced by a touristic trip provider who wants …
Direct chemical grafted curcumin on halloysite nanotubes as dual-responsive prodrug for pharmacological applications
2016
Covalently functionalized halloysite nanotubes (HNTs) were successfully employed as dual-responsive nanocarriers for curcumin (Cur). Particularly, we synthesized HNT-Cur prodrug with a controlled curcumin release on dependence of both intracellular glutathione (GSH) and pH conditions. In order to obtain HNT-Cur produgs, halloysite was firstly functionalized with cysteamine through disulphide linkage. Afterwards, curcumin molecules were chemically conjugated to the amino end groups of halloysite via Schiff's base formation. The successful functionalization of halloysite was proved by thermogravimetric analysis, FT-IR spectroscopy, dynamic light scattering and scanning electron microscopy. Ex…
Electrochemical formation of N,N′-diarylhydrazines by dehydrogenative N–N homocoupling reaction
2020
Hydrazines represent a class of compounds of high interest due to their applicability as versatile starting materials in many important transformations. Herein, we report a synthetic approach to hydrazine derivatives using commercially available anilines and an anodic dehydrogenative N-N coupling reaction as the key step.
Inside Back Cover: Structure-Based Design of an RNA-Bindingp-Terphenylene Scaffold that Inhibits HIV-1 Rev Protein Function (Angew. Chem. Int. Ed. 50…
2013
ChemInform Abstract: Synthesis of Isoindolo[1,4]benzoxazinone and Isoindolo[1,5]benzoxazepine: Two New Ring Systems of Pharmaceutical Interest.
2016
Abstract Two new ring systems, isoindolo[1,4]benzoxazinone and isoindolo[1,5]benzoxazepine, were conveniently synthesized through cyclization of suitably substituted isoindole derivatives. Some of the new compounds exhibited antiproliferative activity against a wide range of human tumor cell lines with GI 50 mean values at low micromolar level (3.72–5.13 μM).