Borrowing Hydrogen Amination Reactions: A Complex Analysis of Trends and Correlations of the Various Reaction Parameters

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(12), P. 7142 - 7198

Published: June 1, 2022

Borrowing hydrogen or the autotransfer amination is a powerful approach to create single C–N bonds, starting from stable and readily available substrates: amines alcohols. It considered as one of most atom-efficient green methods synthesize complex amines. Herein, we attempted arrange array existing data in comprehensive structured manner determine correlations between experimental conditions catalysis outcome both within different groups catalysts defined using machine analysis. For each type N-nucleophiles (aromatic, aliphatic, heteroaromatic amines, amides), efficient working were suggested, including attributing optimal base temperature regime for metal.

Language: Английский

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Homogeneous Nickel-Catalyzed Sustainable Synthesis of Quinoline and Quinoxaline under Aerobic Conditions

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 85(23), P. 14971 - 14979

Published: Nov. 11, 2020

Dehydrogenative coupling-based reactions have emerged as an efficient route toward the synthesis of a plethora heterocyclic rings. Herein, we report efficacious, nickel-catalyzed two important heterocycles such quinoline and quinoxaline. The catalyst is molecularly defined, phosphine-free, can operate at mild reaction temperature 80 °C. Both be easily assembled via double dehydrogenative coupling, starting from 2-aminobenzyl alcohol/1-phenylethanol diamine/diol, respectively, in shorter span time. This environmentally benign synthetic protocol employing inexpensive rival many other transition-metal systems that been developed for fabrication putative heterocycles. Mechanistically, dehydrogenation secondary alcohol follows clean pseudo-first-order kinetics exhibits sizable kinetic isotope effect. Intriguingly, this provides example storing trapped hydrogen ligand backbone, avoiding metal-hydride formation. Easy regeneration oxidized form under aerobic/O2 oxidation makes eco-friendly easy to handle.

Language: Английский

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Recent advances in nickel-catalyzed C–C and C–N bond formation via HA and ADC reactions

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(19), P. 4213 - 4227

Published: Jan. 1, 2021

In this review article, recent advances in nickel-catalyzed hydrogen auto-transfer (HA) and acceptorless dehydrogenative coupling (ADC) reactions for the construction of C–C C–N bonds have been discussed.

Language: Английский

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Recent advances in pincer–nickel catalyzed reactions

Dalton Transactions, Journal Year: 2021, Volume and Issue: 50(10), P. 3394 - 3428

Published: Jan. 1, 2021

The utility of pincer−nickel complexes in catalyzing reactions such as cross−coupling, oxidation, (de)hydrogenation, hydrofunctionalization, C−H activation and CO₂ functionalization has been reviewed from a synthetic mechanistic point view.

Language: Английский

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Ruthenium(ii) complexes with N-heterocyclic carbene–phosphine ligands for the N-alkylation of amines with alcohols

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(15), P. 3451 - 3461

Published: Jan. 1, 2021

A Ru catalyst with the hetero-bidentate NHC-phosphine ligand, which realizes N-alkylation of amines alcohols improved catalytic activity.

Language: Английский

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Pincer–Ruthenium-Catalyzed Reforming of Methanol─Selective High-Yield Production of Formic Acid and Hydrogen

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(6), P. 3605 - 3617

Published: Feb. 27, 2023

A series of NNN pincer–ruthenium complexes the type (R2NNN)RuCl2(CH3CN) based on bis(imino)pyridine ligands were synthesized and characterized. These pincer ruthenium acetonitrile complexes, along with their phosphine carbonyl counterparts, tested for reforming methanol in water presence a base. The catalyst (Cy2NNN)RuCl2(PPh3) was found to be most efficient comparison other considered catalysts. Among bases screened, KOtBu (1.5 equiv respect water) give best results at temperatures as low 100 °C. Under these conditions, while (0.2 mol %) mixture 2:1 ratio gave yield up 81% each hydrogen formic acid (FA) 100% selectivity, corresponding reaction 2 % 90% 73% FA 80% selectivity. On hand, (0.8 catalyzed 3:1 methanol/water good yields (84%) 95% cross-verified by using it reduce unsaturated compounds determining reduced product, which consistent. Isotope-labeling studies suggest involvement C–H activation part catalytic cycle not rate-determining step (RDS) an average secondary KIE 1.96. observed have first-order dependence rate concentration both methanol. DFT are agreement this, σ-bond metathesis leading elimination first molecule is computed RDS either moles or that carbon dioxide 3 hydrogen. Ru–H species (Cy2NNN)RuCl(H) plays decisive role unprecedented selectivity toward FA. In its choice undergo O–H (that completes cycle) leads dioxide, chooses former kinetically more favored 4.58 kcal/mol. current system comprising pincer-ruthenium phosphines gives high H2 operating temperature offers immense promise transformation clean-burning high-value

Language: Английский

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Electrocatalytic Oxidation of Methanol and Ethanol with 3d-Metal Based Anodic Electrocatalysts in Alkaline Media Using Carbon Based Electrode Assembly

Inorganic Chemistry, Journal Year: 2024, Volume and Issue: 63(6), P. 3005 - 3018

Published: Feb. 1, 2024

Homogeneous electrocatalytic systems based on readily available, earth-abundant, inexpensive base metals Ni, Co, and Cr have been formulated for the electro-oxidation of alcohols (methanol ethanol) that constitute a key half-cell component direct alcohol fuel cells (DAFCs). Notably, excellent results were obtained both methanol as well ethanol while operating with assembly all-non-noble working counter electrode consisting glassy carbon graphite rod, respectively. Using NaOH supporting electrolyte, Ni/Co/Cr metal salts their bis(iminopyridine) complexes used anodic electrocatalysts reactions, among them, catalytic Co outperformed corresponding Ni Cr. The system comprising CoCl2.·6H2O [10 mM] + [6 M] at room temperature emerged best electrocatalyst [5 (ca. 522.5 ± 13.5 mA cm–2 1.4 V) 209 25 1.34 V). It was observed regardless starting alcohol, end product is dioxide, all which gets trapped sodium carbonate (up to 97% yield), thereby mitigating any possible hazards greenhouse gas emission. Inferences from FETEM, FESEM, EDS analysis electrolyte solution residues deposited surface provide evidence mostly homogeneous nature reaction mixture molecular catalyst being major contributor toward activity apart minor role played by trace heterogeneous particles. current cell non-noble electrodes utilizing an salt/complex not only in good densities high-energy power-source DAFCs but also generates high-value offers exciting avenue.

Language: Английский

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Cyclometalated Iridium Complex-Catalyzed N-Alkylation of Amines with Alcohols via Borrowing Hydrogen in Aqueous Media

ACS Omega, Journal Year: 2020, Volume and Issue: 5(42), P. 27723 - 27732

Published: Oct. 19, 2020

This paper develops a methodology for cyclometalated iridium complex-catalyzed N-alkylation of amines with alcohols via borrowing hydrogen in the aqueous phase. The catalyst-mediated displays high activity (S/C up to 10,000 and yield 96%) ratio amine/imine (up >99:1) broad range substrates 46 examples) using water as green eco-friendly solvent. Most importantly, this transformation is simple, efficient, can be performed at gram scale, showcasing its potential industrially synthesizing N-alkylamine compounds.

Language: Английский

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N-Alkylation of Amines with Alcohols Catalyzed by Manganese(II) Chloride or Bromopentacarbonylmanganese(I)

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(3), P. 2254 - 2263

Published: Jan. 26, 2021

A manganese-catalyzed N-alkylation reaction of amines with alcohols via hydrogen autotransfer strategy has been demonstrated. The developed practical catalytic system including an inexpensive, nontoxic, commercially available MnCl2 or MnBr(CO)5 as the metal salt and triphenylphosphine a ligand provides access to diverse aromatic, heteroaromatic, aliphatic secondary in moderate-to-high yields. In addition, this operationally simple protocol is scalable gram level suitable for synthesizing heterocycles such indole resveratrol-derived known be active Alzheimer's disease.

Language: Английский

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[(PPh₃)₂NiCl₂]-Catalyzed C–N Bond Formation Reaction via Borrowing Hydrogen Strategy: Access to Diverse Secondary Amines and Quinolines

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(9), P. 6994 - 7001

Published: April 27, 2021

Commercially available [(PPh3)2NiCl2] was found to be an efficient catalyst for the mono-N-alkylation of (hetero)aromatic amines, employing alcohols deliver diverse secondary including drug intermediates chloropyramine (5b) and mepyramine (5c), in excellent yields (up 97%) via borrowing hydrogen strategy. This method shows a superior activity (TON up 10000) with broad substrate scope at low loading 1 mol % short reaction time. Further, this strategy is also successful accessing various quinoline derivatives following acceptorless dehydrogenation pathway.

Language: Английский

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