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

Organic & Biomolecular Chemistry, Год журнала: 2021, Номер 20(4), С. 831 - 839

Опубликована: Дек. 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.

Язык: Английский

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Four- and five-coordinate nickel(ii) complexes bearing new diphosphine–phosphonite and triphosphine–phosphite ligands: catalysts for N-alkylation of amines

RSC Advances, Год журнала: 2022, Номер 12(8), С. 4510 - 4520

Опубликована: Янв. 1, 2022

A series of nickel( ii ) complexes supported by the new tridentate P3 and tetradentate P4 ligands act efficiently as catalysts for N -alkylation primary amines with alcohols.

Язык: Английский

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Development of a Mild and Efficient Process for Ir-Catalyzed N-Alkylation of 4-Bromopyridin-2-amine with a Primary Alcohol via Borrowing Hydrogen

Organic Process Research & Development, Год журнала: 2024, Номер 28(8), С. 3414 - 3422

Опубликована: Июль 25, 2024

We report herein the development and scale up of an Ir-catalyzed N-alkylation reaction between a 4-bromopyridin-2-amine (1) (4-(5-(1,1-difluoroethyl)-1,2,4-oxadiazol-3-yl)bicyclo[2.2.2]octan-1-yl)methanol (2) proceeding via borrowing hydrogen process. The traditional approach alcohol oxidation followed by reductive amination posed challenges that are attributed to poor nucleophilicity 2-aminopyridine derivative resulting in lower isolated yields. Several catalysts bases were evaluated for successful 1 with 2, Ir (III) catalyst combination LiOt-Bu as base was found provide optimal conversion. process successfully demonstrated on 1.5 kg afforded >70% yield 3 without need sealed reactor or any other specialized equipment.

Язык: Английский

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Modulating the electronics of orthometalated RuII-NHC complexes via substitution patterns or NHC donors: Studies towards the impacts in catalysis

Journal of Organometallic Chemistry, Год журнала: 2021, Номер 951, С. 122008 - 122008

Опубликована: Июль 30, 2021

Язык: Английский

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Dehydrative amination of benzhydrols with electron-withdrawing group-substituted 2-aminopyridines utilizing Au(iii)/TPPMS catalyst system in water

Organic & Biomolecular Chemistry, Год журнала: 2022, Номер 20(20), С. 4183 - 4188

Опубликована: Янв. 1, 2022

We report a method for gold( iii )/TPPMS-catalyzed direct amination of benzhydols using 2-aminopyridines with poor nucleophilic character in water.

Язык: Английский

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