Hydrogen Transfer Reactions of Carbonyls, Alkynes, and Alkenes with Noble Metals in the Presence of Alcohols/Ethers and Amines as Hydrogen Donors

Catalysts, Journal Year: 2018, Volume and Issue: 8(12), P. 671 - 671

Published: Dec. 19, 2018

Hydrogen transfer reactions have exceptional importance, due to their applicability in numerous synthetic pathways, with academic as well industrial relevance. The most important transformations are, e.g., reduction, ring-closing, stereoselective reactions, and the synthesis of heterocycles. present review provides insights into hydrogen condensed phase presence noble metals (Rh, Ru, Pd) catalysts. Since H-donor molecules (such alcohols/ethers amines (1°, 2°, 3°)) acceptor (alkenes (C=C), alkynes (C≡C), carbonyl (C=O) compounds) play a crucial role from mechanistic viewpoints, summary points out key differences interpretation current contributions corresponding historical achievements well.

Language: Английский

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Organochalcogen ligands in catalysis of oxidation of alcohols and transfer hydrogenation

Dalton Transactions, Journal Year: 2020, Volume and Issue: 49(36), P. 12503 - 12529

Published: Jan. 1, 2020

Organochalcogen compounds have been used as the building blocks for development of a variety catalysts that studied comprehensively during last two decades several chemical transformations. Transfer hydrogenation (reduction carbonyl to alcohols) and oxidation alcohols (conversion their respective ketones aldehydes) are also among such Some compilations available in literature on catalysts, based organochalcogen ligands, applications Heck reaction, Suzuki other related aspects. review articles published different aspects transfer hydrogenation. However, no article is syntheses use ligated these reactions. In this perspective, survey developments pertaining synthetic (S/Se/Te) reactions has made. addition covering chalcogen metal complexes nanoparticles (NPs), emphasis placed efficient conversion substrates catalytic reactions, diversity potential mechanistic catalysis. It includes analysis comparison (in terms efficiency) between unique class without donor. The future scope area highlighted.

Language: Английский

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Ruthenacycles and Iridacycles as Transfer Hydrogenation Catalysts

Molecules, Journal Year: 2021, Volume and Issue: 26(13), P. 4076 - 4076

Published: July 3, 2021

In this review, we describe the synthesis and use in hydrogen transfer reactions of ruthenacycles iridacycles. The review limits itself to metallacycles where a ligand is bound bidentate fashion either ruthenium or iridium via carbon-metal sigma bond, as well dative bond from heteroatom an N-heterocyclic carbene. Pincer complexes fall outside scope. Described are applications (asymmetric) hydrogenation aldehydes, ketones, imines, reductive aminations. Oxidation reactions, i.e., classical Oppenauer oxidation, which reverse hydrogenation, dehydrogenations oxidations with oxygen, described. Racemizations alcohols secondary amines also catalyzed by

Language: Английский

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Beyond Metal-Arenes: Monocarbonyl Ruthenium(II) Catalysts for Transfer Hydrogenation Reactions in Water and in Cells

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(16), P. 10798 - 10823

Published: Aug. 1, 2023

With the aim to design water-soluble organometallic Ru(II) complexes acting as anticancer agents catalyzing transfer hydrogenation (TH) reactions with biomolecules, we have synthesized four monocarbonyl (1–4), featuring 1,4-bis(diphenylphosphino)butane (dppb) ligand and different bidentate nitrogen (N∧N) ligands, of general formula [Ru(OAc)CO(dppb)(N∧N)]n (n = +1, 0; OAc acetate). The compounds been characterized by methods, including 1H 31P NMR spectroscopies, electrochemistry, well single-crystal X-ray diffraction in case 1 4. also studied for their hydrolysis an aqueous environment catalytic regioselective reduction nicotinamide adenine dinucleotide (NAD+) 1,4-dihydronicotinamide (1,4-NADH) solution sodium formate a hydride source. Moreover, stoichiometric oxidation 1,4-NADH investigated UV–visible spectrophotometry spectroscopy. results suggest that cycle can start directly from intact compound or its aquo/hydroxo species (in 1–3) afford ruthenium complex. Overall, initial structure–activity relationships could be inferred which point toward influence extension aromatic N∧N cationic 1–3 on TH both reduction/oxidation processes. While complex 3 is most active NADH O2, neutral 4, picolinamidate ligand, stands out catalyst NAD+, while being completely inactive oxidation. convert pyruvate into lactate presence formate, albeit scarce efficiency. In any case, all compounds, intermediates observed even isolated 1–3. Together, insights kinetic electrochemical characterization that, 1–3, sees H-transfer rate-limiting step, whereas NAD+ H-donor, step substrate, suggested density functional theory (DFT) calculations. Compound stable respect solution, appears operate via mechanism other derivatives. Finally, activity ability form reactive oxygen (ROS) cancerous nontumorigenic cells vitro. Noteworthy, conversion aldehydes alcohols achieved three catalysts living cells, assessed fluorescence microscopy. Furthermore, formation intermediate upon treatment cancer cell extracts has detected this study paves way application non-arene-based biological environment.

Language: Английский

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An Annelated Mesoionic Carbene (MIC) Based Ru(II) Catalyst for Chemo- and Stereoselective Semihydrogenation of Internal and Terminal Alkynes

Organometallics, Journal Year: 2020, Volume and Issue: 39(17), P. 3212 - 3223

Published: Aug. 30, 2020

The catalytic utility of [RuL1(CO)2I2] (1), containing an annelated π-conjugated imidazo-naphthyridine-based mesoionic carbene (MIC) ligand (L1), is evaluated for E-selective alkyne semihydrogenation. precatalyst 1, in combination with 2 equiv AgBArF, semihydrogenates a broad range internal alkynes molecular hydrogen (5 bar) water. (E)-Alkenes are accessed high yields, and number reducible functional groups tolerated. A chelate MIC two cis carbonyls provide well-defined platform at the Ru center hydrogenation isomerization. loss iodides presence render electron deficient thus formation metal vinylidenes terminal avoided. This leveraged semihydrogenation by same system isopropyl alcohol. Reaction profile, isomerization, kinetic, DFT studies reveal initial to (Z)-alkene, which further isomerizes (E)-alkene via metal-catalyzed Z → E

Language: Английский

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Deep eutectic solvents as H2-sources for Ru(II)-catalyzed transfer hydrogenation of carbonyl compounds under mild conditions

Tetrahedron, Journal Year: 2021, Volume and Issue: 83, P. 131997 - 131997

Published: Feb. 9, 2021

Language: Английский

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Preparation of Ru-Based Systems Through Metal Carbonyl Cluster Decomposition for the Base-Free 5-Hydroxymethylfurfural (HMF) Oxidation

Molecules, Journal Year: 2025, Volume and Issue: 30(10), P. 2120 - 2120

Published: May 10, 2025

Metal carbonyl clusters, which can be seen as monodispersed and atomically defined nanoparticles stabilized by CO ligands, were used to prepare Ru-based catalysts with tuned basic properties conduct the 5-hydroxymethylfurfural (HMF) aerobic oxidation produce 2,5-furandicarboxylic acid (FDCA) in base-free conditions. The controlled decomposition of cluster [HRu3(CO)11]−, a methodology not yet applied Ru for this reaction, on different supports focusing controlling tuning support allowed formation small mean diameter around 1 nm. catalytic systems obtained resulted more activity HMF than those prepared through common salt-impregnation technique, deposition materials functionalities has avoiding use solutions reaction. characterization CO2-TPD Mg(Al)O from layered double hydroxide hydrotalcites composition activation disclosure an important correlation between selectivity FDCA fraction weak sites, is decreased calcination treatment at increased temperature.

Language: Английский

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Synthesis of N-alkoxy amines and hydroxylamines via the iridium-catalyzed transfer hydrogenation of oximes

Organic & Biomolecular Chemistry, Journal Year: 2022, Volume and Issue: 20(32), P. 6394 - 6399

Published: Jan. 1, 2022

An efficient and practical strategy for the construction of N -alkoxy amines hydroxylamines through corresponding oximes is described via an Ir-catalyzed acid-assisted system with high yields a good substrate scope.

Language: Английский

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Transfer Hydrogenation from 2-propanol to Acetophenone Catalyzed by [RuCl2(η6-arene)P] (P = monophosphine) and [Rh(PP)2]X (PP = diphosphine, X = Cl−, BF4−) Complexes

Catalysts, Journal Year: 2020, Volume and Issue: 10(2), P. 162 - 162

Published: Feb. 1, 2020

The reduction of ketones through homogeneous transfer hydrogenation catalyzed by transition metals is one the most important routes for obtaining alcohols from carbonyl compounds. interest this method increases when opportune catalytic precursors are able to perform transformation in an asymmetric fashion, generating enantiomerically enriched chiral alcohols. This reaction has been extensively studied terms catalysts and variety substrates. A large amount information about possible mechanisms available nowadays, which high importance development systems with excellent outcomes conversion, enantioselectivity Turn Over Frequency. On other side, many mechanistic aspects still unclear, especially those have shown only moderate performances hydeogenation. case neutral [RuCl2(η6-arene)(P)] cationic [Rh(PP)2]X (X = anion; P PP mono- bidentate phosphine, respectively) complexes. Herein, a summary known Transfer Hydrogenation these complexes provided continuous focus on more relevant features.

Language: Английский

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Flat and Efficient HCNN and CNN Pincer Ruthenium Catalysts for Carbonyl Compound Reduction

Organometallics, Journal Year: 2019, Volume and Issue: 38(5), P. 1127 - 1142

Published: Feb. 21, 2019

The bidentate HCNN dicarbonyl ruthenium complexes trans,cis-[RuCl2(HCNN)(CO)2] (1–3) and trans,cis-[RuCl2(ampy)(CO)2] (1a) were prepared by reaction of [RuCl2(CO)2]n with 1-[6-(4′-methylphenyl)pyridin-2-yl]methanamine, benzo[h]quinoline (HCNN), 2-(aminomethyl)pyridine (ampy) ligands. Alternatively, the derivatives 1–3 obtained from RuCl3 hydrate HCO2H HCNN. pincer CNN cis-[RuCl(CNN)(CO)2] (4) was isolated 1 NEt3. monocarbonyl trans-[RuCl2(HCNN)(PPh3)(CO)] (5–7) synthesized [RuCl2(dmf)(PPh3)2(CO)] ligands, while diacetate trans-[Ru(OAc)2(HCNN)(PPh3)(CO)] (8) [Ru(OAc)2(PPh3)2(CO)]. Carbonylation cis-[RuCl(CNN)(PPh3)2] CO afforded [RuCl(CNN)(PPh3)(CO)] (9–11). Treatment 9 Na[BArf]4 PPh3 gave cationic complex trans-[Ru(CNN)(PPh3)2(CO)][BArf4] (12). 1–4, in presence or PCy3, 5–12 catalyzed transfer hydrogenation (TH) acetophenone (a) 2-propanol at reflux (S/C = 1000–100000 TOF up to 100000 h–1). Compounds 1–3, 6 8–10 proven catalyze TH carbonyl compounds, including α,β-unsaturated aldehydes bulky ketones 10000 h–1, respectively). PCy3 5 (HY) a (H2, 30 bar) 70 °C 2000–10000). Complex active HY diaryl aryl methyl ketones, leading complete conversion S/C 10000.

Language: Английский

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