1,720,978 research outputs found
Mechanosynthesis of sulfonamides via a telescopic, environmentally friendly, and cost-effective process
No full textHerein, we demonstrate a solvent-free mechanochemical approach involving a one-pot-double-step procedure mediated by solid sodium hypochlorite (NaOCl·5H2O) for the synthesis of sulfonamides. The protocol entails a tandem oxidation-chlorination reaction on disulfides in the presence of a catalytic solid acidic species, followed by an amination prompted by a Lewis acid-base solid inorganic reagent. The methodology works smoothly with aromatic and aliphatic disulfides and amines. The purification process pays due attention to environmental concerns and avoids harsh conditions to obtain pure sulfonamide products. Some relevant biologically active compounds have been prepared with this procedure
Ammonia Synthesis by Mechanochemistry
Full text linkThe design and use of organic, inorganic, and metal-based catalysts is critical to academic and industrial laboratories all around the world. In this framework, ammonia production embodies the most iconic use of catalysis. This review aims to describe the most recent and exciting developments in the mechanocatalytic preparation of ammonia
Boundary behaviour for solutions of elliptic singular equations with a gradient term
No full textWe investigate the homogeneous Dirichlet boundary value problem for a class of second-order nonlinear elliptic partial differential equations with a gradient term and singular data. Under general conditions on the data, we study the behaviour of
the solution near the boundary of the domain. Under suitable additional conditions we also investigate the second-order term in the asymptotic expansion of the solution in terms of the distance from the boundary
Mechanochemistry for Healthcare: Revealing the Nitroso Derivatives Genesis in the Solid State
Full text linkNitroso derivatives with unique characteristics have been extensively studied in various fields, including biology and clinical research. Although there has been substantial investigation of “nitrosable” components in many drugs and commonly consumed nutrients, there is still a need for a higher awareness about their formation and characterization. This study demonstrates how these derivatives can be produced through a mechanochemical procedure under solid-state conditions. The results include synthesizing previously unknown compounds with potential biological and pharmaceutical applications, such as a nitrosamine derived from a Diclofenac-like structure
Tandem Baeyer–Villiger/Wittig/oxa-Michael addition: One-step to 5-substituted γ-lactones
Full text linkThe results reported in this study provide a practical protocol for the construction, in one single step of synthetically important γ-lactones in good yields starting from α-hydroxy cyclobutanone, H2O2 and several stabilized phosphonium ylides. Our synthetic strategy relies on a tandem Baeyer–Villiger oxidation/Wittig reaction/oxa-Michael addition
Mechanically accelerated catalytic hydrogenation: correlating physical state, reaction rate, and interface area
No full textThis study thoroughly examines the role of mechanochemistry in organic synthesis by analysing the factors affecting the mechanochemical reduction process of unsaturated and oxidized compounds. Hydride species and hydrogen gas are generated in situ by mixing a diboron compound with a stoichiometric amount of water. The process is tested against several substrates to determine how the physical state of the reagents influences the reduction technique. The study aims to thoroughly investigate the correlation between the mixing process, reaction rate, and interface area
Mechanically processed Sardinian wool promotes C-C bond synthesis under solvent-free conditions
No full textThe tangible environmental concerns of the last few decades are prompting science to a new sustainable paradigm for chemical reactions and a circular economy. In the present manuscript, complying with this dichotomy, Sardinian wool is presented as a promising material for organic synthesis. Aldol and nitro-aldol additions, and Knoevenagel reactions were demonstrated with high efficiency under wool-promoted and solvent-free conditions, paving the way to novel approaches for converting wool biomass waste into value-added products for C-C bond formation
The Heyns Rearrangement: Synthetic Routes Beyond Carbohydrate Chemistry
Full text linkThis concept review describes the recent achievements on the Heyns rearrangement appeared in literature over the last decade and aims to provide the reader with a general overview of the fundamental synthetic advances in this research area
Boundary behaviour for solution to elliptic singular equations with a gradient term
No full textWe investigate the homogeneous Dirichlet boundary value problem for a class of second order nonlinear elliptic partial differential equations with a gradient term and singular data. Under general
conditions on the data, we study the behaviour of the solution near the boundary of the domain.
Under suitable additional conditions we also investigate the second order term in the asymptotic expansion of the solution in terms of the distance from boundary
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