Methylation of amines is a fundamental and commonly used reaction in organic synthesis. Many methods are known including various reductive methylations using formaldehyde, formic acid, or carbon dioxide in the presence of reductants. However, several of these methods suffer from limited substrate scope and chemoselectivity because of the different nucleophilicities of substrates. In this respect, the combination of carbonates and hydrosilanes is a valuable methylation source in the presence of Pt-based catalysts. This highly tunable method allows for methylation of both aromatic and aliphatic amines, and chemoselective methylation of aminoalcohols and diamines. Notably, the in situ-formed catalyst can also be used for the reduction of carbonates to methanol at room temperature. Mechanistic insights on intermediates formed during the reaction pathway were obtained by using ESI mass spectrometry.
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http://dx.doi.org/10.1002/chem.201502917 | DOI Listing |
Environ Sci Technol
January 2025
School of Environmental Science and Engineering, Shenzhen Key Laboratory of Municipal Solid Waste Recycling Technology and Management, Southern University of Science and Technology, Shenzhen 518055, China.
Solid-liquid biphasic absorbents are a promising solution for overcoming the high-energy consumption challenge faced by liquid amine-based CO capture technologies. However, their practical applications are often hindered by difficulties in separating viscous solid-phase products. This study introduces a novel nonaqueous absorbent system (PD/PZ/NMP) composed of 4-amino-1-methylpiperidine (PD), piperazine (PZ), and -methyl-2-pyrrolidone (NMP), engineered to produce easily separable powdery products.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
The oxomolybdenum complexes Mo1, Mo2 and Mo3, which share a common ONO donor ligand backbone but differ in their peripheral substituents, were explored to study their reactivity in organic transformations in water. The ligand backbones of Mo1 and Mo2 were covalently linked to a methyl group and a single hydrophobic -hexadecyl chain an ether linkage, respectively. The complex Mo3 was found to possess two -hexadecyl chains attached to the ligand backbone a common amine-N.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Department of Microbiology, Virology and Immunology, I. Horbachevsky Ternopil State Medical University, 46001 Ternopil, Ukraine.
Background: In the era of resistance, the design and search for new "small" molecules with a narrow spectrum of activity that target a protein or enzyme specific to a certain bacterium with high selectivity and minimal side effects remains an urgent problem of medicinal chemistry. In this regard, we developed and successfully implemented a strategy for the search for new hybrid molecules, namely, the not broadly known [2-(3-R-1-[1,2,4]-triazol-5-yl)phenyl]amines. They can act as "building blocks" and allow for the introduction of certain structural motifs into the desired final products in order to enhance the antistaphylococcal effect.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
School of Biological Sciences and The Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Sphingolipidomic mass spectrometry has provided valuable information-and surprises-about sphingolipid structures, metabolism, and functions in normal biological processes and disease. Nonetheless, many noteworthy compounds are not routinely determined, such as the following: most of the sphingoid bases that mammals biosynthesize de novo other than sphingosine (and sometimes sphinganine) or acquire from exogenous sources; infrequently considered metabolites of sphingoid bases, such as N-(methyl)-derivatives; "ceramides" other than the most common N-acylsphingosines; and complex sphingolipids other than sphingomyelins and simple glycosphingolipids, including glucosyl- and galactosylceramides, which are usually reported as "monohexosylceramides". These and other subspecies are discussed, as well as some of the circumstances when they are likely to be seen (or present and missed) due to experimental conditions that can influence sphingolipid metabolism, uptake from the diet or from the microbiome, or as artifacts produced during extraction and analysis.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Department of Pediatrics, National Jewish Health, Denver, CO 80206, USA.
The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel that is dysfunctional in individuals with cystic fibrosis (CF). The permeability of CFTR can be experimentally manipulated though different mechanisms, including activation via inducing the phosphorylation of residues in the regulatory domain as well as altering the gating/open probability of the channel. Phosphorylation/activation of the channel is achieved by exposure to compounds that increase intracellular cAMP, with forskolin and IBMX commonly used for this purpose.
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