Vitreoscillahemoglobin: a natural carbene transfer catalyst for diastereo- and enantioselective synthesis of nitrile-substituted cyclopropanes

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(17), P. 6853 - 6858

Published: Jan. 1, 2023

we developed an environmentally friendly strategy that combines in situ generation of a diazo reagent with biocatalysis for the asymmetric cyclopropanation olefins.

Language: Английский

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Green synthesis of tetra-substituted 2H-pyrans catalyzed by lipase in aqueous medium

Biocatalysis and Biotransformation, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 8

Published: Jan. 15, 2025

An efficient and environmental method was employed to synthesize multi-substituted 2H-pyran from methyl coumalate β-keto esters or diketones. Porcine pancreas lipase (PPL) can catalyze this transformation in high yields (74–96%) aqueous medium (H2O: DMSO = 2:1) under mild conditions (60 °C). The reported strategy exhibits functional group compatibility broad substrate scope. In addition, it provides access a variety of tetra-substituted 2H-pyrans which are considered privileged scaffolds with diverse biological activities.

Language: Английский

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Optimization and Enhancement of the Peroxidase-like Activity of Hemin in Aqueous Solutions of Sodium Dodecylsulfate

ACS Omega, Journal Year: 2023, Volume and Issue: 8(45), P. 42878 - 42899

Published: Nov. 3, 2023

Iron porphyrins play several important roles in present-day living systems and probably already existed very early life forms. Hemin (= ferric protoporphyrin IX = heme b), for example, is the prosthetic group at active site of peroxidases, catalyzing oxidation a number different types reducing substrates after hemin first oxidized by hydrogen peroxide as oxidizing substrate enzyme. The peroxidases consists hydrophobic pocket which embedded noncovalently kept place through coordination iron atom to proximal histidine side chain protein. It this partially local environment enzyme determines efficiency with sequential reactions proceed site. Free hemin, has been separated from protein moiety known aggregate an aqueous solution exhibits low catalytic activity. Based on previous reports use surfactant micelles solubilize free nonaggregated state, peroxidase-like activity presence sodium dodecyl sulfate (SDS) concentrations below above critical concentration SDS micelle formation (critical micellization (cmc)) was systematically investigated. In most experiments, 3,3′,5,5′-tetramethylbenzidine (TMB) applied pH 7.2. clearly had positive effect reaction terms initial rate yield, even cmc. highest correlated cmc value, demonstrated three HEPES concentrations. 4-(2-hydroxyethyl)-1-piperazineethanesulfonate salt (HEPES) served buffer substance also accelerating reaction. At cmc, addition l-histidine (l-His) resulted further concentration-dependent increase until maximal reached optimal l-His concentration, corresponding ideal mono-l-His ligation hemin. Some results obtained can be understood basis molecular dynamics simulations, indicated existence intermolecular interactions between SDS. Preliminary experiments SDS/dodecanol vesicles 7.2 showed that vesicles, exhibited similar case micelles. This supports hypothesis micelle- or vesicle-associated ferrous may have played role primitive catalysts membranous prebiotic compartment before cellular emerged.

Language: Английский

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Metal‐Free Synthesis of α‐Iminonitriles via Visible Light Photoredox Catalysis

Asian Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 12(11)

Published: May 20, 2023

Abstract A reaction of imidazo[1,2‐ α ]pyridine and Zhdankin reagent (IBA‐N 3 ) is described for the synthesis ‐iminonitriles via visible light photoredox catalysis. series substituted were efficiently prepared in moderate to good yields under mild conditions. This transformation goes through a radical ring‐opening process furnish corresponding products. Notably, does not require toxic cyanide reagents, expensive metal photocatalysts excessive oxidants.

Language: Английский

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Sustainable tandem acylation/Diels–Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

Beilstein Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 20, P. 1308 - 1319

Published: June 6, 2024

Tandem Diels–Alder reactions are often used for the straightforward formation of complex natural compounds and fused polycyclic systems contained in their precursors. In second step this reaction, regio- stereochemically controlled intramolecular cyclization leads to versatile nitrogen-containing tricyclic systems. However, these useful organic transformations usually carried out highly toxic solvents such as benzene, toluene, chloroform, etc. Despite recent efforts by 'green chemists', synthetic chemists still use traditional many reactions, even though safer alternatives available. addition harmful effects petrochemical on environment, prediction that resources will run near future has led chemists' explore can be derived from renewable effectively various transformations. context, we have shown first time 100% atom-economical tandem reaction between aminofuranes maleic anhydride successfully vegetable oils waxes. The was sunflower seed oil, olive oleic acid lauryl myristate under mild conditions. A series epoxyisoindole-7-carboxylic bisepoxyisoindole-7-carboxylic acids were obtained good yields after a practical isolation procedure. results study demonstrate potential materials provide medium is more sustainable than conventional cascade repeatedly without significant degradation. These also allow completed less time, with energy consumption higher yields.

Language: Английский

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Sodium Copper Chlorophyllin: A Sustainable Bioinspired Catalyst for the Aerobic Oxidative Synthesis of Nitrogen Heterocycles and the Oxidative Cyanation of Tertiary Amines

ChemistrySelect, Journal Year: 2024, Volume and Issue: 9(41)

Published: Oct. 29, 2024

Abstract A remarkably simple and straightforward protocol has been reported showcasing sodium copper chlorophyllin (SCC) as an eco‐friendly, bioinspired catalyst for the aerobic oxidative synthesis of pharmaceutically prevalent nitrogen‐containing heterocycles, such benzimidazoles quinoxalines. This reaction was performed in green solvent water, using oxidant, molecular oxygen. SCC displayed exceptional efficiency, congruent with prevailing metal/non‐metal‐based regime without requiring additives. The exhibited excellent recyclability upto three cycles benzimidazole reaction. benign strategy successfully applied synthesizing a bioactive quinoxaline i. e ., Tyrphostin AG1296, promising candidate melanoma treatment. catalytic activity explored another privileged moiety α ‐aminonitriles, via α‐ cyanation tertiary amines under conditions. progressed mild, easy‐to‐use, convenient cyanide source, ethyl cyanoformate, attractive solvent, methanol, precluding acidic media. efficiently recycled ‐aminonitriles synthesis. Overall, utility biodegradable, robust SCC, eco‐friendly solvents water oxidants O 2, mild conditions, devoid additives, renders present work viable academic industrial research.

Language: Английский

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