The mechanochemical, solvent‐free, highly regioselective, rhodium‐catalyzed C−H methylation of (hetero)arenes is reported. The reaction shows excellent functional‐group compatibility and is ...demonstrated to work for the late‐stage C−H methylation of biologically active compounds. The method requires no external heating and benefits from considerably shorter reaction times than previous solution‐based C−H methylation protocols. Additionally, the mechanochemical approach is shown to enable the efficient synthesis of organometallic complexes that are difficult to generate conventionally.
Catalytic C−H methylation proceeds efficiently under solvent‐free, mechanochemical conditions, including the late‐stage functionalization of biologically active substrates and otherwise difficult‐to‐make metalacyclic complexes.
The development of an efficient method for the site‐selective substitution of unprotected phenols has long been considered as an attractive but challenging task. Herein, we describe a highly chemo‐ ...and ortho‐selective substitution reaction of phenols with α‐aryl α‐diazoacetates with commercially available (C6F5)3B as the catalyst. This reaction proceeds under simple and mild conditions with high efficiency, it features a wide substrate scope and can be easily scaled up.
Commercially available (C6F5)3B as the catalyst enables the highly chemo‐ and ortho‐selective substitution of phenols with α‐aryl α‐diazoacetates. This reaction proceeds under simple and mild conditions with high efficiency, features a wide substrate scope, and can be easily scaled up.
The area of transition-metal-catalyzed direct arylation through cleavage of C---H bonds has undergone rapid development in recent years, and is becoming an increasingly viable alternative to ...traditional cross-coupling reactions with organometallic reagents. In particular, palladium and ruthenium catalysts have been described that enable the direct arylation of (hetero)arenes with challenging coupling partners--including electrophilic aryl chlorides and tosylates as well as simple arenes in cross-dehydrogenative arylations. Furthermore, less expensive copper, iron, and nickel complexes were recently shown to be effective for economically attractive direct arylations.
The direct functionalization of CH bonds in organic compounds has recently emerged as a powerful and ideal method for the formation of carbon–carbon and carbon–heteroatom bonds. This Review provides ...an overview of CH bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.
The ideal case: The direct functionalization of CH bonds in organic compounds has recently emerged as a powerful and ideal method for the formation of carbon–carbon and carbon–heteroatom bonds. This Review provides an overview of CH functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.
An efficient approach to patterning 2D MoS2 through covalent functionalization of electron beam lithography (EBL)‐defined guiding patterns has been demonstrated by A. Hirsch et al. in their ...Communication (DOI: 10.1002/chem.202102021). This approach opens a convenient avenue for spatially designing and engineering MoS2 nanostructures, and would benefit further exploration of MoS2‐based devices and facilitate efficient manufacture.
Magnetic nanoparticles have attracted significant attention due to their exceptional features and versatile applications, including water and/or wastewater treatment. Discharge of heavy metals and ...other contaminants into water resources is a concern due to the detrimental effects on humans and the environment. Grafting magnetic nanoparticles with amino functional groups yields aminated or amino-functionalized magnetic nanoparticles, which show better results than bare magnetic nanoparticles in water treatment applications. Their magnetic nature is crucial for cost-effective and greener pollutant removal from water since they are magnetically separated and reused without a major change in structure and efficiency. In this review, the synthesis, separation and adsorption processes, and future perspectives for amino-functionalized magnetic nanoparticles are discussed in addition to their applicability in water treatment. Several important works have also been discussed for the removal of metals, radionuclides, organic contaminants, dyes and pathogens from water. The influence of parameters, such as magnetic nanoparticle dosage, pH, contact time, ion selectivity, and recyclability are also presented.
Display omitted
•Amino-functionalized magnetic nanoparticles (MNPs) for water treatment were discussed.•Recent advances in the fabrication of amino-functionalized MNPs were reviewed.•Removal of metals, radionuclides, organic contaminants and pathogens from water.•Insightful discussion on existing challenges and future developments.
Site‐selective functionalization of C−H bonds in small complex molecules is a long‐standing challenge in organic chemistry. Herein, we report a broadly applicable and site‐selective aromatic C−H ...dibenzothiophenylation reaction. The conceptual advantage of this transformation is further demonstrated through the two‐step C−H 18Ffluorination of a series of marketed small‐molecule drugs.
A broadly applicable and site‐selective late‐stage aromatic 18Ffluorination reaction is reported. A collection of three electronically different dibenzothiophenes enables 18F labeling of a series of small complex molecules.
Carbon nanotubes (CNTs) have been widely studied and used for the construction of electrochemical biosensors owing to their small size, cylindrical shape, large surface-to-volume ratio, high ...conductivity and good biocompatibility. In electrochemical biosensors, CNTs serve a dual purpose: they act as immobilization support for biomolecules as well as provide the necessary electrical conductivity for electrochemical transduction. The ability of a recognition molecule to detect the analyte is highly dependent on the type of immobilization used for the attachment of the biomolecule to the CNT surface, a process also known as biofunctionalization. A variety of biofunctionalization methods have been studied and reported including physical adsorption, covalent cross-linking, polymer encapsulation etc. Each method carries its own advantages and limitations. In this review we provide a comprehensive review of non-covalent functionalization of carbon nanotubes with a variety of biomolecules for the development of electrochemical biosensors. This method of immobilization is increasingly being used in bioelectrode development using enzymes for biosensor and biofuel cell applications.
Ordered thiol-functionalized microporous silica with BET surface area 1136.64 m(2)/g and high thiol group density was prepared by co-condensation of 3-mercaptopropyltrimethoxysilane and ...tetramethoxysilane in the hydroalcoholic medium with cetyltrimethylammonium bromide. These samples were characterized through BET analysis, XRD, TEM, IR and Raman spectroscopy, (29)Si NMR and elemental analysis. The sorption behaviors and mechanisms of Pb(2+) and Cd(2+) on the samples were studied. The maximum sorption amounts of Pb(2+) and Cd(2+) were 130 and 39 mg/g, respectively. Freundlich isotherm was proved to describe the sorption data better than Langmuir isotherm and pseudo second order kinetic model could fit the sorption kinetic processes well. The pH and electrolyte NaNO(3) influenced the sorption of Pb(2+) and Cd(2+) on the samples significantly. According to hard and soft acids and bases theory and the information analyzed from XPS, the sorption mechanisms could be explained as primary chemical adsorption and secondary physical adsorption.
Robust, reliable, and quantitative detection of biomarkers at ultra-low concentration is of great importance in clinical settings. Biosensor, an analytical device used for sensitive and selective ...detection of biomarkers offers various advantages over the conventional clinical diagnosis, which is both time consuming and not suitable for point of care/onsite diagnosis. A revolution in the understanding and synthesis of nanomaterials in the last couple of decades contributed significantly to the development of the biosensors in terms of sensitivity, catalytic activity, biocompatibility, and robustness. Additionally, nanomaterials help in miniaturization of the sensing platform and helping in the commercial success of portable biosensor kits. Surface engineering equally contributed to the biosensor development by ensuring a reproducible and stable sensing surface, efficient analyte-biorecognition element interaction, and reduced fouling effect in biological solution. Due to nanomaterial integration and surface engineering, biosensors are now equally sensitive to the lab-based sophisticated instruments to detect a wide range of molecules of clinical significance. In this review, various types of biosensors, their designs, and their working principles have been discussed. A detailed account of various types of nanomaterials, their functionalization and characterization have also been discussed. The analytical performances of biosensors for both clinical validation and analyte detection have been incorporated here. The recent trends in advanced biosensors, such as smartphone interface for biosensing, nanozymes, lab-on-a-chip based detection methods have been discussed.
PDF
