Manganese(III) Porphyrin‐Catalyzed Dehydrogenation of Alcohols to form Imines, Tertiary Amines and Quinolines

Chemistry - A European Journal, Journal Year: 2019, Volume and Issue: 25(25), P. 6439 - 6446

Published: March 19, 2019

Manganese(III) porphyrin chloride complexes have been developed for the first time as catalysts acceptorless dehydrogenative coupling of alcohols and amines. The reaction has applied to direct synthesis imines, tertiary amines quinolines where only hydrogen gas and/or water are formed by-product(s). mechanism is believed involve formation a manganese(III) alkoxide complex which degrades into aldehyde hydride species. latter reacts with alcohol form thereby regenerates complex.

Language: Английский

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Design and Synthesis of Zirconium‐Containing Coordination Polymer Based on Unsymmetric Indolyl Dicarboxylic Acid and Catalytic Application on Borrowing Hydrogen Reaction

Advanced Synthesis & Catalysis, Journal Year: 2018, Volume and Issue: 360(22), P. 4293 - 4300

Published: Aug. 28, 2018

Abstract Catalytic borrowing hydrogen reaction is a very attractive transformation in the field of C‐alkylation reaction. In this work, new Zr (Zirconium)‐containing coordination polymer containing unsymmetric indolyl dicarboxylic acid 1‐(carboxymethyl)‐1H‐indole‐5‐carboxylic (H 2 CIA) was synthesized by way solvothermal synthetic route and characterized powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission (TEM), Nitrogen adsorption‐desorption, fourier transform infrared spectroscopy photoelectronic (XPS). The Zr‐CIA employed as catalyst for acetophenone derivatives presence benzyl alcohol. addition, also observed to be effective alcohols with high yields alkylation products were achieved. Mechanism investigations conducted better understand catalysts transformations. Meanwhile, could reused at least five times without notable decrease activity selectivity. magnified image

Language: Английский

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Ligand-Free Ru-Catalyzed Direct sp³ C–H Alkylation of Fluorene Using Alcohols

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 85(4), P. 2277 - 2290

Published: Jan. 6, 2020

The sp3 C-H alkylation of 9H-fluorene using alcohol and a Ru catalyst via the borrowing hydrogen concept has been described. This reaction was catalyzed by [Ru(p-cymene)Cl2]2 complex (3 mol %) exhibited broad scope with different alcohols, allowing primary secondary alcohols to be employed as nonhazardous greener alkylating agents formation environmentally benign water byproduct. A variety underwent selective exclusive mono-C9-alkylation in good excellent isolated yield (26 examples, 50-92% yield), whereas this absence any external oxidants furnished tetrasubstituted alkene major product. Furthermore, base-mediated hydroxylation synthesized derivatives afforded 9H-hydroxy-functionalized quaternary fluorene yield.

Language: Английский

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Cyclometalated Dicarbonyl Ruthenium Catalysts for Transfer Hydrogenation and Hydrogenation of Carbonyl Compounds

Organometallics, Journal Year: 2018, Volume and Issue: 37(13), P. 2136 - 2146

Published: June 18, 2018

The dicarbonyl complex RuCl2(L)2(CO)2 (1) was easily prepared by reaction of ruthenium chloride hydrate with formic acid and L (L = (2,6-Me2C6H3)PPh2) in ethanol at reflux, via the [RuCl2(CO)2]n intermediate. Alternatively, 1 obtained from [RuCl2(CO)3]2 CO elimination. Reaction NEt3 toluene reflux afforded cyclometalated derivative RuCl{(2-CH2-6-MeC6H3)PPh2}(L)(CO)2 (2). A simple one-pot synthesis 2 achieved treatment RuCl3 acid, L, NEt3. complexes [Ru{(2-CH2-6-MeC6H3)PPh2}(NN)(CO)2]Cl (NN ethylenediamine, 3; 2-(aminomethyl)pyridine, 4; (R,R)-1,2-diphenylethane-1,2-diamine, 5) were isolated corresponding dinitrogen ligand methanol reflux. Complexes 1–4 catalyze transfer hydrogenation (TH) acetophenone 2-propanol (S/C 1000 TOF up to 30 000 h–1) alkali base (1–5 mol %), whereas 5 leads (S)-1-phenylethanol 68% ee. derivatives 1–5 (HY) several ketones (H2, bar) 70 °C MeOH EtOH KOtBu (2 %) 25 14 h–1). Addition NN ligands situ increases both TH HY activity, ampy displaying better performance. Heating cationic 3 solid state solution decarbonylation, affording neutral monocarbonyl compound RuCl{(2-CH2-6-MeC6H3)PPh2}(en)(CO) (6) which found active ketone HY.

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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Preparation of monocarbonyl ruthenium complexes bearing bidentate nitrogen and phosphine ligands and their catalytic activity in carbonyl compound reduction

Dalton Transactions, Journal Year: 2019, Volume and Issue: 48(33), P. 12560 - 12576

Published: Jan. 1, 2019

A series of novel monocarbonyl ruthenium catalysts containing bidentate dinitrogen or/and diphosphine ligands are easily obtained through a general and straightforward approach.

Language: Английский

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N-Alkylation of organonitrogen compounds catalyzed by methylene-linked bis-NHC half-sandwich ruthenium complexes

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 20(4), P. 831 - 839

Published: Dec. 27, 2021

An efficient ruthenium-catalyzed N-alkylation of amines, amides and sulfonamides has been developed employing novel pentamethylcyclopentadienylruthenium(II) complexes bearing the methylene linked bis(NHC) ligand bis(3-methylimidazol-2-ylidene)methane. The acetonitrile complex 2 proven particularly effective with a broad range substrates low catalyst loading (0.1-2.5 mol%) high functional group tolerance under mild conditions. A total 52 N-alkylated organonitrogen compounds including biologically relevant scaffolds were synthesized from (hetero)aromatic aliphatic using alcohols or diols as alkylating agents in up to 99% isolated yield, even on gram-scale reactions. In case sulfonamides, it is first example transition-metal NHC ligands.

Language: Английский

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Acetate Acetylacetonate Ampy Ruthenium(II) Complexes as Efficient Catalysts for Ketone Transfer Hydrogenation

ChemCatChem, Journal Year: 2020, Volume and Issue: 12(13), P. 3537 - 3544

Published: April 18, 2020

Abstract The mixed acetate acetylacetonate (acac) ruthenium(II) phosphine complexes Ru(OAc)(acac)P 2 [P =(PPh 3 ) , Ph P(CH 4 PPh (dppb)] were prepared by protonation of Ru(OAc) (PPh with acetylacetone in dichloromethane. Reaction the dppb derivative 2‐(aminomethyl)pyridine (ampy) affords complex Ru(OAc)(acac)(ampy)(dppb), which converts to [Ru(acac)(ampy)(dppb)](OAc) toluene at 90 °C. In former ampy ligand is monodentate and coordinates through NH ‐moiety. isolated acac are active catalysts for transfer hydrogenation ketones loadings as low 0.01 mol%, having a strong accelerating effect. Several aromatic aliphatic ketone substrates converted their corresponding alcohols, different electronic influences substituents on acetophenone tolerated.

Language: Английский

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Preparation of the Ru₃(CO)₈-pyridine-alcohol cluster and its use for the selective catalytic transformation of primary to secondary amines

Dalton Transactions, Journal Year: 2018, Volume and Issue: 47(39), P. 14033 - 14040

Published: Jan. 1, 2018

The synthesis of pyridine alcohol based ruthenium carbonyl clusters Ru3(hep)2(CO)8 (1), Ru3(hpp)2(CO)8 (2), and Ru3(bhmp-H)2(CO)8 (3) {hep-H = 2-(2-hydroxyethyl)pyridine, hpp-H 2-(3-hydroxypropyl)pyridine bhmp-H2 2,6-bis(hydroxymethyl)pyridine} has been carried out by the reaction corresponding pyridine-alcohol ligands with Ru3(CO)12. Clusters 1-3 have characterized using elemental analysis, NMR, FT-IR, mass spectrometry single-crystal X-ray structures. were explored for selective catalytic transformation primary amines into secondary alcohols as mono-alkylating agents via hydrogen transfer reactions. All three display efficient activity 1 being most effective.

Language: Английский

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Ru(O₂CCF₃)₂(PPh₃)₂ and ruthenium phosphine complexes bearing fluoroacetate ligands: synthesis, characterization and catalytic activity

Dalton Transactions, Journal Year: 2019, Volume and Issue: 48(14), P. 4625 - 4635

Published: Jan. 1, 2019

The versatile precursor Ru(O₂CCF₃)₂(PPh₃)₂ was isolated and used for the synthesis of ruthenium(ii) trifluoroacetate complexes, active in ketone transfer hydrogenation.

Language: Английский

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