First-Row Transition Metal (De)Hydrogenation Catalysis Based On Functional Pincer Ligands

Chemical Reviews, Journal Year: 2018, Volume and Issue: 119(4), P. 2681 - 2751

Published: Dec. 31, 2018

The use of 3d metals in de/hydrogenation catalysis has emerged as a competitive field with respect to "traditional" precious metal catalyzed transformations. introduction functional pincer ligands that can store protons and/or electrons expressed by metal-ligand cooperativity and ligand redox-activity strongly stimulated this development conceptual starting point for rational catalyst design. This review aims at providing comprehensive picture the utilization first-row transition hydrogenation dehydrogenation related synthetic concepts relying on these such hydrogen borrowing methodology. Particular emphasis is put implementation relevance cooperating redox-active within mechanistic scenarios.

Language: Английский

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Azines: synthesis, structure, electronic structure and their applications

Organic & Biomolecular Chemistry, Journal Year: 2019, Volume and Issue: 17(37), P. 8486 - 8521

Published: Jan. 1, 2019

Azines (2,3-diaza-1,3-butadienes): structure, electronic tautomerism, and their applications in organic synthesis, medicinal chemistry materials chemistry.

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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Metal–ligand cooperative approaches in homogeneous catalysis using transition metal complex catalysts of redox noninnocent ligands

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 20(2), P. 296 - 328

Published: Dec. 6, 2021

Catalysis offers a straightforward route to prepare various value-added molecules starting from readily available raw materials. The catalytic reactions mostly involve multi-electron transformations. Hence, compared the inexpensive and 3d-metals, 4d 5d-transition metals get an extra advantage for performing as heavier transition prefer two-electron redox events. However, sustainable development, these expensive scarce heavy metal-based catalysts need be replaced by inexpensive, environmentally benign, economically affordable 3d-metal catalysts. In this regard, metal-ligand cooperative approach involving metal complexes of noninnocent ligands attractive alternative. synergistic participation redox-active during electron transfer events allows transformations using interesting chemical 5d-metals well. Herein we summarize up-to-date literature report on approaches few selected types reactions.

Language: Английский

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Metal-coordinated azoaromatics: Strategies for sequential azo-reduction, isomerization and application potential

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 475, P. 214895 - 214895

Published: Oct. 21, 2022

Language: Английский

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Alcohol Dehydrogenation-Triggered Selective C3-Alkylation of Indoles by Homogeneous Azo-aromatic Cobalt Catalysts

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(9), P. 5827 - 5843

Published: April 10, 2023

Herein, we report azo-benzimidazole containing cobalt complexes (1-3) for alcohol dehydrogenation-triggered C3-alkylation of indoles. In 1-3, ligands are redox noninnocent and showed facile irreversible L/L• reduction followed by Co(II)/Co(I) in close-lying potentials. Taking advantage events the first aerial dehydrogenation alcohols to their corresponding carbonyl compounds is explored. Subsequently, indole was studied using as alkylating agents. The developed catalytic protocol found be efficient very selective. It has a broad substrate scope good functional group tolerance. As far aware, it homogeneous catalyst agent. Detailed mechanistic studies, including deuterium labeling experiment, have suggested borrowing hydrogen method indole. coordinated ligand, cooperatively with couple, oxidized alkoxide radical pathway result compound (Scheme 1), which on subsequent condensation generates alkylideneindolenine intermediate "X". Reduction "X" an azo-anion Co(I) resulted C3-alkylated

Language: Английский

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N2H4 as traceless mediator for homo- and cross- aryl coupling

Nature Communications, Journal Year: 2018, Volume and Issue: 9(1)

Published: Nov. 5, 2018

Transition-metal catalyzed couplings of aryl halides or arenes with organometallics, as well direct reductive coupling two halides, are the predominant methods to synthesize biaryls. However, stoichiometric amounts metals inevitably utilized in these reactions, either pre-generation organometallic reagents acting reductant situ, thus producing quantitative metal waste. Herein, we demonstrate that this longstanding challenge can be overcome N2H4 a surrogate. The fundamental innovation strategy is N2 and H2 generated side products, which readily escape from system after reaction. success both homo- cross-coupling various electrophiles bearing wide range functional groups manifests powerfulness versatility strategy. Furthermore, cross-couplings series alkaloids, amino acids steroids exemplify application protocol functionalization biologically active molecules.

Language: Английский

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Synthesis and biological activity of structurally diverse phthalazine derivatives: A systematic review

Bioorganic & Medicinal Chemistry, Journal Year: 2019, Volume and Issue: 27(18), P. 3979 - 3997

Published: Aug. 1, 2019

Language: Английский

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Solvent-Free N-Alkylation and Dehydrogenative Coupling Catalyzed by a Highly Active Pincer-Nickel Complex

Organometallics, Journal Year: 2020, Volume and Issue: 39(11), P. 2162 - 2176

Published: May 22, 2020

The synthesis and characterization of a pincer-nickel complex the type (iPr2NNN)NiCl2(CH3CN) is reported here. We have demonstrated utility this (0.02 0.002 mol %) for catalytic N-alkylation amines using various alcohols. Under solvent-free conditions, while highest yield (ca. 90%) was obtained alkylation 2-aminopyridine with naphthyl-1-methanol, excellent turnovers (34000 TONs) were observed 4-methoxybenzyl alcohol. To demonstrate synthetic these systems, high-yield reactions (up to 98%) been probed representative substrates higher loading catalyst (4 %). DFT studies indicate that β-hydride elimination RDS alcohol dehydrogenation, N-alkylated product can be formed either via hydrogenation rate-determining σ-bond metathesis or by alcoholysis has imine insertion as RDS. All corresponding resting states HRMS (ESI) analysis. labeling experiments are also complementary show evidence involvement benzylic C–H bond in kCHH/kCHD value about 2.5. This method applied accomplish efficient (2000 dehydrogenative coupling leading benzimidazoles.

Language: Английский

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Recent advances in the synthesis of five‐ and six‐membered heterocycles as bioactive skeleton: A concise overview

ChemistrySelect, Journal Year: 2022, Volume and Issue: 7(6)

Published: Feb. 8, 2022

Abstract Heterocyclic compounds play a tremendous role in the field of medicinal chemistry due to their association with diverse pharmacological properties. Most pharmaceutical drugs used medicines possess wide range heterocyclic nucleus. It was decided basis on literature studies that various synthetic protocols like microwave‐assisted, nanocatalysed, green synthesis, click reaction, and multicomponent routes could be for betterment purity products, selectivity, better yields products. We have focused attention development strategies above‐mentioned moieties because N ‐, O ‐ S containing seemed owing diversity biological activities viz . antioxidant, anticancer, anticonvulsant, anti‐inflammatory, neuroprotective, antiproliferative, anti‐obesity, antihyperglycemic, antihypercholesteroler, antiulcer, antidiabetic, antileishmanial, antitrypanosomal, antibiotic, etc In this review article, an overview applications preparation five‐membered six‐membered two or more heteroatoms ( , ) at different‐different positions along different potent competent candidates against diseases is presented last 10–15 years.

Language: Английский

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