Borrowing Hydrogen and Acceptorless Dehydrogenative Coupling in the Multicomponent Synthesis of N‐Heterocycles: A Comparison between Base and Noble Metal Catalysis

European Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 2021(46), P. 6206 - 6223

Published: Nov. 4, 2021

Abstract Acceptorless dehydrogenative coupling reactions (ADC) and hydrogen transfer strategies (HT) provide a powerful tool in the multicomponent formation of N ‐ heterocycles. A broad variety complex products can be obtained starting from simple, cheap commercially available reagents. The protocols are highly atom‐efficient, as water, dihydrogen, or some cases peroxide, only by‐products. Moreover, neither further reducing oxidizing agents, nor external general required. Especially base metal‐catalyzed become ever more important. Therefore, recent years, various different manganese, iron, cobalt, nickel copper catalysts have been developed. This Minireview highlights progress that has made by using abundant metal complexes to promote cyclizations for heterocycles compares their performance with noble catalyst systems.

Language: Английский

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Dehydrogenative Synthesis of Quinolines and Quinazolines via Ligand-Free Cobalt-Catalyzed Cyclization of 2-Aminoaryl Alcohols with Ketones or Nitriles

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(19), P. 12596 - 12607

Published: Sept. 26, 2022

We present a convenient and efficient protocol to synthesize quinolines quinazolines in one pot under mild conditions. A variety of substituted were synthesized good excellent yields (up 97% yield) from the dehydrogenative cyclizations 2-aminoaryl alcohols ketones catalyzed by readily available Co(OAc)2·4H2O. This cobalt catalytic system also showed high activity reactions 2-aminobenzyl with nitriles, affording various quinazoline derivatives 95% yield). The offers an environmentally benign approach for synthesis N-heterocycles employing earth-abundant salt ligand-free

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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Single-Molecular Mn(I)-Complex-Catalyzed Tandem Double Dehydrogenation Cross-Coupling of (Amino)Alcohols under Solventless Conditions with the Liberation of H₂ and H₂O

ACS Sustainable Chemistry & Engineering, Journal Year: 2022, Volume and Issue: 10(22), P. 7362 - 7373

Published: May 24, 2022

Sustainable chemical production requires fundamentally new types of catalysts and catalytic technologies. The development coherent robust systems based on earth-abundant transition metals is essential but extremely challenging. Herein, we report the first a single Mn(I)-PNP catalyzed tandem C–C C–N bond formation via double dehydrogenative coupling amino alcohols with primary alcohols. current method covers wide range substrates, including aryl, aliphatic, acyclic, cyclic alcohols, as well to provide diverse N-heterocyclic compounds (pyridine quinoline derivatives) in good excellent yields (50 examples). reaction proceeds under benign, solventless conditions liberation molecular hydrogen water only byproducts. Various control labeling experiments kinetic, nuclear magnetic resonance, mechanistic studies suggest that operates acceptorless pathway, selectively assimilating desired N-heterocycles. Several selective activation/formation reactions occur sequentially amine–amide metal–ligand cooperation.

Language: Английский

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Borrowing Hydrogen β-Phosphinomethylation of Alcohols Using Methanol as C1 Source by Pincer Manganese Complex

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(47), P. 25545 - 25552

Published: Nov. 14, 2023

Herein, we report a manganese-catalyzed three-component coupling of β-H containing alcohols, methanol, and phosphines for the synthesis γ-hydroxy via borrowing hydrogen strategy. In this development, methanol serves as sustainable C1 source. A variety aromatic aliphatic substituted alcohols could undergo dehydrogenative cross-coupling process efficiently deliver corresponding β-phosphinomethylated alcohol products in moderate to good yields. Mechanistic studies suggest that transformation proceeds sequential manner including catalytic dehydrogenation, aldol condensation, Michael addition, hydrogenation.

Language: Английский

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Recent advances on N-heterocyclic carbene transition metal complexes for dehydrogenative catalysis using alcohols

Catalysis Today, Journal Year: 2020, Volume and Issue: 370, P. 114 - 141

Published: Oct. 20, 2020

Language: Английский

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Nickel catalyzed sustainable synthesis of benzazoles and purines via acceptorless dehydrogenative coupling and borrowing hydrogen approach

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(33), P. 7217 - 7233

Published: Jan. 1, 2021

Herein we report nickel-catalyzed sustainable synthesis of a few chosen five-membered fused nitrogen heterocycles such as benzimidazole, purine, benzothiazole, and benzoxazole via acceptorless dehydrogenative functionalization alcohols. Using bench stable, easy to prepare, inexpensive Ni(ii)-catalyst, [Ni(MeTAA)] (1a), featuring tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)), wide variety polysubstituted derivatives were prepared coupling alcohols with 1,2-diaminobenzene, 4,5-diaminopyrimidine, 2-aminothiphenol, 2-aminophenol, respectively. A array benzimidazoles also borrowing hydrogen approach involving donors 2-nitroanilines acceptors. control experiments performed understand the reaction mechanism.

Language: Английский

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Dendrons containing boric acid and 1,3,5-tris(2-hydroxyethyl)isocyanurate covalently attached to silica-coated magnetite for the expeditious synthesis of Hantzsch esters

Scientific Reports, Journal Year: 2021, Volume and Issue: 11(1)

Published: Jan. 27, 2021

Abstract A new multifunctional dendritic nanocatalyst containing boric acid and 1,3,5-tris(2-hydroxyethyl)isocyanurate covalently attached to core–shell silica-coated magnetite (Fe 3 O 4 @SiO 2 @PTS-THEIC-(CH ) OB(OH) was designed properly characterized by different spectroscopic or microscopic methods as well analytical techniques used for mesoporous materials. It found that the combination of both aromatic π–π stacking boron–oxygen ligand interactions affords supramolecular arrays dendrons. Furthermore, use makes this catalyst a good choice, from corrosion, recyclability cost points view. The catalytic activity Fe , an efficient magnetically recoverable catalyst, investigated synthesis polyhydroacridines (PHAs) polyhydroquinolines (PHQs) via one-pot multicomponent reactions dimedone and/or ethyl acetoacetate, aldehydes ammonium acetate in EtOH under reflux conditions. Very low loading high quantitative yields desired PHAs PHQs products, short reaction times, wide scope substrates, eliminating any toxic heavy metals corrosive reagents modification simple work-up procedure are remarkable advantages green protocol. An additional advantage magnetic nanoparticles is its ability be separated recycled easily mixture with minimal efforts six subsequent runs without significant loss activity. This can extended two- three-dimensional covalent organic frameworks applications.

Language: Английский

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Iron-catalysed quinoline synthesis via acceptorless dehydrogenative coupling

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(23), P. 6573 - 6578

Published: Jan. 1, 2022

An iron-catalysed atom-economical and straightforward methodology for the synthesis of quinolines from α-2-aminoaryl alcohols secondary is presented.

Language: Английский

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TEMPO/PhI(OAc)₂ promotes the α-aminophosphinoylation of alcohols with amines and H-phosphine oxides in aqueous medium

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(19), P. 3860 - 3865

Published: Jan. 1, 2024

The aminophosphinoylation of alcohols with amines and H-phosphine oxides provides an efficient mild approach to access various α-aminoalkylphosphine in good yields tolerance functional groups using H 2 O as a clean solvent.

Language: Английский

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