Tetrahedron Letters, Год журнала: 2022, Номер 101, С. 153926 - 153926
Опубликована: Июнь 6, 2022
Язык: Английский
Russian Chemical Reviews, Год журнала: 2023, Номер 92(12), С. RCR5104 - RCR5104
Опубликована: Дек. 1, 2023
After the appearance of green chemistry concept, which was introduced in vocabulary early 1990s, its main statements have been continuously developed and modified. Currently, there are 10–12 cornerstones that should form basis for an ideal chemical process. This review analyzes accumulated experience achievements towards design products processes reduce or eliminate use generation hazardous substances. The presents views leading Russian scientists specializing various fields this subject, including homogeneous heterogeneous catalysis, fine basic organic synthesis, electrochemistry, polymer chemistry, based on bio-renewable feedstocks energetic compounds materials. A new approach to quantitative evaluation environmental friendliness by authors is described. <br> bibliography includes 1761.
Язык: Английский
Процитировано
41
Journal of the American Chemical Society, Год журнала: 2024, Номер 146(5), С. 3065 - 3074
Опубликована: Янв. 28, 2024
Chiral 1-pyrrolines containing a nitrile motif serve as crucial structural scaffolds in biologically active molecules and exhibit diversity building blocks owing to their valuable functional groups; however, the asymmetric synthesis of such compounds remains largely unexplored. Herein, we present an enantio- diastereoselective method for α-chiral nitrile-containing 1-pyrroline derivatives bearing vicinal stereocenters through design introduction chiral cyclopropenimine-based bifunctional catalysts featuring thiourea moiety. This entails highly stereoselective conjugate addition α-iminonitriles wide array enones, followed by cyclocondensation, thereby affording series cyanopyrroline derivatives, some which contain all-carbon quaternary centers. Moreover, demonstrate synthetic utility this strategy performing gram-scale reaction with 1% catalyst loading, along variety chemoselective transformations product, including vildagliptin analogue. Finally, showcase selective all four stereoisomers products
Язык: Английский
Процитировано
14
Reaction Chemistry & Engineering, Год журнала: 2022, Номер 7(2), С. 269 - 274
Опубликована: Янв. 1, 2022
The behaviour of solvents in solid-supported proline organocatalysts is explored using NMR relaxation measurements coupled with reaction screening. Solvents a lower affinity for the solid surface lead to higher reactivity.
Язык: Английский
Процитировано
21
Molecules, Год журнала: 2024, Номер 29(10), С. 2166 - 2166
Опубликована: Май 7, 2024
Within the realm of organic synthesis, photocatalysis has blossomed since beginning last decade. A plethora classical reactivities, such as selective oxidation alcohol and amines, redox radical formation reactive species in situ, indirect activation an substrate for cycloaddition by EnT, have been revised a milder more sustainable fashion via photocatalysis. However, even though spark creativity leads scientists to explore new reactions urgency replacing toxic critical metals that are involved catalysts encouraged chemists find alternatives branch science called organocatalysis. Unfortunately, metal with analogues can be too expensive sometimes; however, this drawback solved reutilization catalyst if it is heterogeneous. The aim review present recent works field heterogeneous photocatalysis, applied enabled continuous flow. In detail, among catalysts, g-CN, polymeric photoactive materials, supported molecular discussed within their specific sections, rather than focusing on types reactions.
Язык: Английский
Процитировано
5
The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(12), С. 7826 - 7837
Опубликована: Май 27, 2022
Indole-decorated glycine derivatives are prepared through an environmentally benign cross-dehydrogenative coupling between N-aryl analogues and indoles (yield of ≤81%). Merging heterogeneous organocatalysis photocatalysis, C–H functionalization has been achieved by selective C-2 oxidation glycines to afford the electrophilic imine followed Friedel–Crafts alkylation with indole. The sustainability process taken into account in reaction design implementation a metal-free recyclable photocatalyst green medium. Scale-up benchmark (gram scale, yield 69%) recycling experiments (over seven runs without loss efficiency) have performed prove robustness protocol. Finally, mechanistic studies were conducted employing electron paramagnetic resonance spectroscopy unveil roles oxygen formation odd-electron species.
Язык: Английский
Процитировано
11
ChemCatChem, Год журнала: 2022, Номер 14(14)
Опубликована: Апрель 22, 2022
Abstract Organocatalyst immobilization onto solid supports represents a promising method for enabling asymmetric organocatalysis while retaining the advantages of heterogeneous catalysts, including catalyst separation, recycling, and use fixed‐bed reactors. Understanding how such heterogenized catalytic systems work is fundamental to develop tailor more efficient ones. Herein, we have elucidated role reactant molecular structure on surface interactions reactivity aldol reactions between benzaldehyde derivatives hydroxyacetone catalyzed by SBA‐15 immobilized L ‐proline. NMR relaxation time analysis reveals that stronger interaction aldehyde reduces reactivity, which attributed reduced access ‐proline sites, hence inhibiting formation enamine intermediate The results show phenomena in these are important considerations selection, opening up new directions explore this area research.
Язык: Английский
Процитировано
7
Molecules, Год журнала: 2023, Номер 28(4), С. 1530 - 1530
Опубликована: Фев. 4, 2023
Novel polyhydroxylated ammonium, imidazolium, and pyridinium salt organocatalysts were prepared through N-alkylation sequences using glycidol as the key precursor. The most active iodide catalyst effectively promoted carbonation of a set terminal epoxides (80 to >95% yields) at low loading (5 mol%), ambient pressure CO2, moderate temperature (75 °C) in batch operations, also demonstrating high recyclability simple downstream separation from reaction mixture. Moving segmented flow conditions with operation thermostated pressurized (8.5 atm) home-made reactors significantly reduced process time (from hours seconds), increasing productivity up 20.1 mmol(product) h-1 mmol(cat)-1, value ~17 times higher than that mode.
Язык: Английский
Процитировано
4
ACS Applied Polymer Materials, Год журнала: 2024, Номер 6(17), С. 10977 - 10985
Опубликована: Авг. 27, 2024
Solid polymer brush-supported molecular catalysts generally exhibit activity comparable to catalysts, but they suffer the problems of decreased with increasing recycled times in reactions. This study explores use brushes a diblock architecture design durable silica-based sulfonic acid catalysts. Two brush materials, differing amounts polystyrene (PS) brush, were prepared by first growing PS using copper-catalyzed ARGET SI-ATRP and poly(vinylimidazole) SI-ATRP. The resulting then reacted 1,3-propane sultone trifluoromethanesulfonic obtain two solid For comparison, without layer was also prepared. These acidic applied synthesize acylals from aldehydes acetic anhydride. acids demonstrated superior compared catalyst. Notably, catalyst protection could be 15 (yield ≥95%) decrease activity; contrast, yield 35% 10th run. Thermogravimetric analysis indicated 3% loss materials for 9.5% layer, after specified numbers runs. Polymer probably finds more applications solid-based
Язык: Английский
Процитировано
1
Molecules, Год журнала: 2024, Номер 29(2), С. 342 - 342
Опубликована: Янв. 10, 2024
The reaction of arylidene-α-amino esters with electrophilic alkenes to yield Michael-type addition compounds is optimized using several phosphines as organocatalysts. transformation very complicated due the generation final compounds, including those derived from 1,3-dipolar cycloadditions. For this reason, selection conditions a complex task and slow acrylic system important complete process. study variation in structural components starting imino ester performed well expansion other electron-poor alkenes. crude products have purity higher than 90% most cases without any purification. A plausible mechanism detailed based on bibliography experimental results. synthesis pyroglutamate entities, after reduction group cyclization, high yields. In addition, hydrolysis group, under acidic media, represents direct access glutamate surrogates.
Язык: Английский
Процитировано
0
Molecules, Год журнала: 2024, Номер 29(18), С. 4350 - 4350
Опубликована: Сен. 13, 2024
A truly organocatalytic approach to the Darzens reaction affording
Язык: Английский
Процитировано
0