Recent advances in sustainable synthesis of N-heterocycles following acceptorless dehydrogenative coupling protocol using alcohols

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(11), P. 2673 - 2709

Published: Jan. 1, 2021

In this review, we have summarized various aspects of homogeneous and heterogeneously catalyzed recent advancements in the synthesis heterocycles following ADC approach.

Language: Английский

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Alcohols as Substrates in Transition-Metal-Catalyzed Arylation, Alkylation, and Related Reactions

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(9), P. 6078 - 6144

Published: April 17, 2024

Alcohols are abundant and attractive feedstock molecules for organic synthesis. Many methods their functionalization require them to first be converted into a more activated derivative, while recent years have seen vast increase in the number of complexity-building transformations that directly harness unprotected alcohols. This Review discusses how transition metal catalysis can used toward this goal. These broadly classified three categories. Deoxygenative functionalizations, representing derivatization C–O bond, enable alcohol act as leaving group formation new C–C bonds. Etherifications, characterized by O–H represent classical reactivity has been modernized include mild reaction conditions, diverse partners, high selectivities. Lastly, chain reactions described, wherein acts mediator formal C–H alkyl backbone. Each these classes transformation will discussed context intermolecular arylation, alkylation, related reactions, illustrating alcohols harnessed

Language: Английский

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Synthesis of N‐Heterocycles via Oxidant‐Free Dehydrocyclization of Alcohols Using Heterogeneous Catalysts

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(48), P. 25188 - 25202

Published: June 17, 2021

N-Heterocycles, such as pyrroles, pyrimidines, quinazolines, and quinoxalines, are important building blocks for organic chemistry the fine-chemical industry. For their synthesis, catalytic borrowing hydrogen acceptorless dehydrogenative coupling reactions of alcohols sustainable reagents have received significant attention in recent years. To overcome problems product separation catalyst reusability, several metal-based heterogeneous catalysts been reported to achieve these transformations with good yields selectivity. In this Minireview, we summarize developments using both noble non-noble synthesize N-heterocycles from N-nucleophiles via dehydrogenation or methodologies. Furthermore, Minireview introduces strategies preparation functionalization corresponding catalysts, discusses reaction mechanisms roles metal electronic states, influence support Lewis acid-base properties on reactions.

Language: Английский

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Manganese(I)-Catalyzed Sustainable Synthesis of Quinoxaline and Quinazoline Derivatives with the Liberation of Dihydrogen

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 85(11), P. 7181 - 7191

Published: May 13, 2020

Direct synthesis of N-heterocycles via the acceptorless dehydrogenative coupling is very challenging and scarcely reported under 3d transition-metal catalysis. Here, we have developed an efficient Mn(I)-catalyzed sustainable various quinoxalines from 1,2-diaminobenzenes 1,2-diols reaction. Further, this strategy was successfully applied for unprecedented quinazolines by reaction 2-aminobenzyl alcohol with primary amides. The present protocol provides atom-economical route quinoxaline quinazoline derivatives employing earth-abundant manganese salt simple phosphine-free NNN-tridentate ligand.

Language: Английский

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Cobalt-catalyzed dehydrogenative functionalization of alcohols: Progress and future prospect

Coordination Chemistry Reviews, Journal Year: 2021, Volume and Issue: 451, P. 214257 - 214257

Published: Oct. 28, 2021

Language: Английский

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Ruthenium Pincer Complex Catalyzed Selective Synthesis of C‐3 Alkylated Indoles and Bisindolylmethanes Directly from Indoles and Alcohols

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(14), P. 2902 - 2910

Published: May 7, 2020

Abstract Herein, we presented Ru‐SNS complex that serves as a useful catalyst for C‐3 alkylation of 1H‐indoles with various aliphatic primary and secondary alcohols including cyclic well benzylic alcohols. The selective synthesis bisindolylmethane derivatives is also achieved from the same set indole alcohol just by altering reaction parameters. Furthermore, sustainable alkylated indoles directly 2‐(2‐nitrophenyl)ethan‐1‐ol catalysed Ru‐complex via “borrowing hydrogen” strategy reported. This protocol provides an atom‐economical route to access structurally important compounds like arundine, vibrindole A tryptamine based derivatives. magnified image

Language: Английский

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Manganese‐Catalyzed Mono‐N‐Methylation of Aliphatic Primary Amines without the Requirement of External High‐Hydrogen Pressure

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(13)

Published: Feb. 1, 2024

Abstract The synthesis of mono‐ N ‐methylated aliphatic primary amines has traditionally been challenging, requiring noble metal catalysts and high‐pressure H 2 for achieving satisfactory yields selectivity. Herein, we developed an approach the selective coupling methanol amines, without hydrogen, using a manganese‐based catalyst. Remarkably, up to 98 % with broad substrate scope were achieved at low catalyst loadings. Notably, due weak base‐catalyzed alcoholysis formamide intermediates, our novel protocol not only obviates addition but also prevents side secondary ‐methylation, supported by control experiments density functional theory calculations.

Language: Английский

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Novel Methodologies for Chemical Activation in Organic Synthesis under Solvent-Free Reaction Conditions

Molecules, Journal Year: 2020, Volume and Issue: 25(16), P. 3579 - 3579

Published: Aug. 6, 2020

One central challenge for XXI century chemists is the development of sustainable processes that do not represent a risk either to humanity or environment. In this regard, search more efficient and clean alternatives achieve chemical activation molecules involved in transformations has played prominent role recent years. The use microwave UV-Vis light irradiation, mechanochemical already widespread many laboratories. Nevertheless, an additional condition “green” comes from point view so-called atom economy. removal solvents reactions generally leads cleaner, economical processes. This review presents several illustrative applications protocols synthesis organic compounds under solvent-free reaction conditions.

Language: Английский

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Iron-Catalyzed Hydrogen Transfer Reduction of Nitroarenes with Alcohols: Synthesis of Imines and Aza Heterocycles

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 86(1), P. 1023 - 1036

Published: Dec. 16, 2020

A straightforward and selective reduction of nitroarenes with various alcohols was efficiently developed using an iron catalyst via a hydrogen transfer methodology. This protocol led specifically to imines in 30–91% yields, good functional group tolerance. Noticeably, starting from o-nitroaniline derivatives, the presence alcohols, benzimidazoles can be obtained 64–72% yields when reaction performed additional oxidant, DDQ, quinoxalines were prepared 1,2-diols 28–96% yields. methodology, unprecedented at for imines, also provides sustainable alternative preparation benzimidazoles.

Language: Английский

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Simple RuCl₃‐catalyzed N‐Methylation of Amines and Transfer Hydrogenation of Nitroarenes using Methanol

ChemCatChem, Journal Year: 2021, Volume and Issue: 13(7), P. 1722 - 1729

Published: Jan. 21, 2021

Abstract Methanol is a potential hydrogen source and C 1 synthon, which finds interesting applications in both chemical synthesis energy technologies. The effective utilization of this simple alcohol organic central importance attracts scientific interest. Herein, we report clean cost‐competitive method with the use methanol as synthon H 2 for selective N ‐methylation amines by employing relatively cheap RuCl 3 .xH O ligand‐free catalyst. This readily available catalyst tolerates various comprising electron‐deficient electron‐donating groups allows them to transform into corresponding ‐methylated products moderate excellent yields. In addition, few marketed pharmaceutical agents (e. g., venlafaxine imipramine) were also successfully synthesized via late‐stage functionalization from feedstock chemicals, highlighting synthetic value advanced reaction. Using platform, attempted tandem reactions selected nitroarenes convert using MeOH under ‐free conditions including transfer hydrogenation nitroarenes‐to‐anilines prepared drug molecules benzocaine butamben) well key intermediates. We further enable one‐shot green syntheses 1‐methylbenzimidazole ortho ‐phenylenediamine (OPDA) coupling partners.

Language: Английский

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