3d-Metal Catalyzed N- and C-Alkylation Reactions via Borrowing Hydrogen or Hydrogen Autotransfer

Chemical Reviews, Journal Year: 2018, Volume and Issue: 119(4), P. 2524 - 2549

Published: Nov. 20, 2018

The conservation of our element resources is a fundamental challenge mankind. development alcohol refunctionalization reactions possible fossil carbon strategy since alcohols can be obtained from indigestible and abundantly available biomass. rare noble metals, frequently used in key technologies such as catalysis, might feasible by replacing them with highly abundant metals. alkylation amines related C–C coupling are early examples reactions. These follow mostly the borrowing hydrogen or autotransfer catalysis concept, many 3d-metal catalysts have been disclosed recent years. In this review, we summarize progress made developing Cu, Ni, Co, Fe, Mn for C–N bond formation using concept. We expect that findings field will inspire others to develop new efficient selective earth-abundant metal applications novel mediated

Language: Английский

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Recent advances in homogeneous borrowing hydrogen catalysis using earth-abundant first row transition metals

Organic & Biomolecular Chemistry, Journal Year: 2018, Volume and Issue: 17(7), P. 1595 - 1607

Published: Sept. 17, 2018

The review highlights the recent advances (2013-present) in use of earth-abundant first row transition metals homogeneous borrowing hydrogen catalysis. utility catalysts based on Mn, Fe, Co, Ni and Cu to promote a diverse array important C-C C-N bond forming reactions is described, including discussion reaction mechanisms, scope limitations, future challenges this burgeoning area sustainable

Language: Английский

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Borrowing Hydrogen for Organic Synthesis

ACS Central Science, Journal Year: 2021, Volume and Issue: 7(4), P. 570 - 585

Published: March 25, 2021

Borrowing hydrogen is a process that used to diversify the synthetic utility of commodity alcohols. A catalyst first oxidizes an alcohol by removing form reactive carbonyl compound. This intermediate can undergo diverse range subsequent transformations before returns "borrowed" liberate product and regenerate catalyst. In this way, alcohols may be as alkylating agents whereby sole byproduct one-pot reaction water. recent decades, significant advances have been made in area, demonstrating many effective methods access valuable products. outlook highlights diversity metal biocatalysts are available for approach, well various performed, focusing on selection most advances. By succinctly describing conveying versatility borrowing chemistry, we anticipate its uptake will increase across wider scientific audience, expanding opportunities further development.

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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Borrowing Hydrogen-Mediated N-Alkylation Reactions by a Well-Defined Homogeneous Nickel Catalyst

ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(10), P. 9051 - 9059

Published: Aug. 19, 2019

We report herein a well-defined and bench-stable azo-phenolate ligand-coordinated nickel catalyst which can efficiently execute N-alkylation of variety anilines by alcohol. demonstrate that the redox-active azo ligand store hydrogen generated during alcohol oxidation redelivers same to an in-situ-generated imine bond result in amines. The reaction has wide scope, large array alcohols directly couple anilines. Mechanistic studies including deuterium labeling substrate establishes borrowing method from pinpoints crucial role moiety present on backbone. Isolation ketyl intermediate its trapped form with radical quencher higher kH/kD for step suggest altogether hydrogen-atom transfer (HAT) reduced backbone pave as opposed conventional metal–ligand bifunctional mechanism. This example clearly demonstrates inexpensive base metal accomplish important coupling help

Language: Английский

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Well-Defined Phosphine-Free Iron-Catalyzed N-Ethylation and N-Methylation of Amines with Ethanol and Methanol

Organic Letters, Journal Year: 2018, Volume and Issue: 20(19), P. 5985 - 5990

Published: Sept. 20, 2018

An iron(0) complex bearing a cyclopentadienone ligand catalyzed N-methylation and N-ethylation of aryl aliphatic amines with methanol or ethanol in mild basic conditions through hydrogen autotransfer borrowing process is reported. A broad range aromatic underwent mono- dimethylation high yields. DFT calculations suggest molecular acts not only as reducing agent but also an additive to displace thermodynamic equilibria.

Language: Английский

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Catalytic C₁ Alkylation with Methanol and Isotope‐Labeled Methanol

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(3), P. 775 - 779

Published: Nov. 20, 2018

Abstract A metal‐catalyzed methylation process has been developed. By employing an air‐ and moisture‐stable manganese catalyst together with isotopically labeled methanol, a series of D‐, CD 3 ‐, 13 C‐labeled products were obtained in good yields under mild reaction conditions water as the only byproduct.

Language: Английский

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Manganese‐Catalyzed β‐Methylation of Alcohols by Methanol

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(4), P. 1485 - 1490

Published: Nov. 19, 2019

Abstract We report an earth‐abundant‐metal‐catalyzed double and single methylation of alcohols. A manganese catalyst, which operates at low catalyst loadings short reaction times, mediates these reactions efficiently. broad scope primary secondary alcohols, including purely aliphatic examples, 1,2‐aminoalcohols can be methylated. Furthermore, alcohol for the synthesis pharmaceuticals has been demonstrated. The system tolerates many functional groups among them hydrogenation‐sensitive examples upscaling is easily achieved. Mechanistic investigations are indicative a borrowing hydrogen or autotransfer mechanism involving bimetallic K‐Mn catalyst. accepts as proton hydride from alcohols efficiently reacts with chalcone via transfer.

Language: Английский

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Manganese catalyzed α-methylation of ketones with methanol as a C1 source

Chemical Communications, Journal Year: 2018, Volume and Issue: 55(3), P. 314 - 317

Published: Dec. 10, 2018

The direct α-methylation of ketones with methanol under hydrogen borrowing conditions using a well-defined manganese PN3P complex as pre-catalyst was, for the first time, achieved. reactions typically proceed at 120 °C 20 h 3 mol% loading and in presence NaOtBu (50 mol%) base. scope reaction was extended to esters.

Language: Английский

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Nonbifunctional Outer-Sphere Strategy Achieved Highly Active α-Alkylation of Ketones with Alcohols by N-Heterocyclic Carbene Manganese (NHC-Mn)

Organic Letters, Journal Year: 2019, Volume and Issue: 21(19), P. 8065 - 8070

Published: Sept. 16, 2019

The unusual nonbifunctional outer-sphere strategy was successfully utilized in developing an easily accessible N-heterocyclic carbene manganese (NHC-Mn) system for highly active α-alkylation of ketones with alcohols. This efficient a wide range and alcohols under mild reaction conditions, also the green synthesis quinoline derivatives. direct mechanism high activity present demonstrate potential catalyst design acceptorless dehydrogenative transformations.

Language: Английский

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