Manganese‐Catalyzed Dehydrogenative Alkylation or α‐Olefination of Alkyl‐Substituted N‐Heteroarenes with Alcohols

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(29), С. 9131 - 9135

Опубликована: Май 2, 2018

Catalysis with earth-abundant transition metals is an option to help save our rare noble-metal resources and especially interesting when novel reactivity or selectivity patterns are observed. We report here on a reaction, namely the dehydrogenative alkylation α-olefination of alkyl-substituted N-heteroarenes alcohols. Manganese complexes developed in laboratory catalyze reaction high efficiency whereas iron cobalt stabilized by same ligands essentially inactive. Hydrogen liberated during bromine iodine functional groups as well olefins tolerated. A variety can be functionalized, benzylic aliphatic alcohols undergo reaction.

Язык: Английский

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Ligand-Controlled Copper(I)-Catalyzed Cross-Coupling of Secondary and Primary Alcohols to α-Alkylated Ketones, Pyridines, and Quinolines

Organic Letters, Год журнала: 2018, Номер 20(3), С. 608 - 611

Опубликована: Янв. 16, 2018

One hexanuclear Cu(I) cluster of 4,6-dimethylpyrimidine-2-thiolate efficiently catalyzes the dehydrogenative cross-coupling secondary and primary alcohols to α-alkylated ketones with high selectivity. This transformation proceeds through a one-pot sequence dehydrogenation alcohols, condensation aldehydes ketones, hydrogenation resulting α,β-unsaturated generate ketones. catalytic system also displays activity for annulation reaction γ-amino- 2-aminobenzyl yield pyridines quinolines, respectively.

Язык: Английский

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Manganese‐Catalyzed Direct Olefination of Methyl‐Substituted Heteroarenes with Primary Alcohols

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(29), С. 9126 - 9130

Опубликована: Май 28, 2018

Abstract Herein, we present the first catalytic direct olefination of methyl‐substituted heteroarenes with primary alcohols through an acceptorless dehydrogenative coupling. The reaction is catalyzed by a complex earth‐abundant transition metal manganese that stabilized bench‐stable NNN pincer ligand derived from 2‐hydrazinylpyridine. environmentally benign, producing only hydrogen and water as byproducts. A large number E ‐disubstituted olefins were selectively obtained high efficiency.

Язык: Английский

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Modular assembly of arenes, ethylene and heteroarenes for the synthesis of 1,2-arylheteroaryl ethanes

Nature Chemistry, Год журнала: 2024, Номер 16(10), С. 1705 - 1714

Опубликована: Июнь 27, 2024

Язык: Английский

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Reaction condition controlled nickel(ii)-catalyzed C–C cross-coupling of alcohols

Organic & Biomolecular Chemistry, Год журнала: 2019, Номер 17(14), С. 3567 - 3574

Опубликована: Янв. 1, 2019

The challenge in the C-C cross-coupling of secondary and primary alcohols using acceptorless dehydrogenation coupling (ADC) is difficulty accurately controlling product selectivities. Herein, we report a controlled approach to diverse range β-alkylated alcohols, α-alkylated ketones α,β-unsaturated ADC methodology employing Ni(ii) 4,6-dimethylpyrimidine-2-thiolate cluster catalyst under different reaction conditions. This could tolerate wide substrates exhibited high activity for annulation with 2-aminobenzyl yield quinolines. work an example precise chemoselectivity control by careful choice

Язык: Английский

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Phosphine Ligand‐Free Ruthenium Complexes as Efficient Catalysts for the Synthesis of Quinolines and Pyridines by Acceptorless Dehydrogenative Coupling Reactions

ChemCatChem, Год журнала: 2019, Номер 11(10), С. 2500 - 2510

Опубликована: Апрель 10, 2019

Abstract A series of phosphine‐free Ru(III)/Ru(II) complexes NH functionalized N ˄ pincer ligands exhibit excellent activity for acceptorless dehydrogenative coupling (ADC) secondary alcohols with 2‐aminobenzyl or γ ‐amino to quinolines and pyridines. Ru(III) [LRuCl 3 ] (L=6‐(3‐R 1 ,5‐R 2 ‐1H‐pyrazol‐1‐yl)‐N‐(pyridin‐2‐yl)pyridin‐2‐amine; a : R =R =H (L1); b =Me (L2); c =H, =CF (L3); d =Ph (L4); 1b Me L=6‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐N‐methyl‐N‐(pyridin‐2‐yl)pyridin‐2‐amine (L2 )) were obtained by refluxing RuCl ⋅ xH O the corresponding ligand in EtOH. Five Ru(II) [LRu(DMSO‐κS)Cl ( L=L1; L=L2; L=L3; L=L4; 2b L=L2 ) formed reducing complex The latter could also be prepared directly Ru(DMSO) 4 Cl These complexes, especially / , exhibited high catalytic efficiency broad functional group tolerance ADC reactions detail mechanistic study indicated was reduced into species, which is active center via Ru−H/N−H bifunctional outer‐sphere mechanism. This protocol provides reliable, atom‐economical environmentally benign procedure C−N C−C bond formation.

Язык: Английский

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Ni‐Catalyzed α‐Alkylation of Unactivated Amides and Esters with Alcohols by Hydrogen Auto‐Transfer Strategy

ChemSusChem, Год журнала: 2018, Номер 11(22), С. 3911 - 3916

Опубликована: Окт. 5, 2018

Abstract A transition‐metal‐catalyzed borrowing hydrogen/hydrogen auto‐transfer strategy allows the utilization of feedstock alcohols as an alkylating partner, which avoids formation stoichiometric salt waste and enables a direct benign approach for construction C‐N C−C bonds. In this study, nickel‐catalyzed α‐alkylation unactivated amides ester ( tert ‐butyl acetate) is carried out by using primary under mild conditions. This bond‐forming reaction catalyzed new, molecularly defined nickel(II) NNN‐pincer complex (0.1–1 mol %) proceeds through hydrogen auto‐transfer, thereby releasing water sole byproduct. addition, N ‐alkylation cyclic Ni‐catalytic conditions demonstrated.

Язык: Английский

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

ChemCatChem, Год журнала: 2021, Номер 13(7), С. 1722 - 1729

Опубликована: Янв. 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.

Язык: Английский

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Transfer Hydrogenation of N- and O-Containing Heterocycles Including Pyridines with H₃N–BH₃ Under the Catalysis of the Homogeneous Ruthenium Precatalyst

Organic Letters, Год журнала: 2024, Номер 26(4), С. 866 - 871

Опубликована: Янв. 25, 2024

In this study, we report a transfer hydrogenation protocol that utilizes borane–ammonia (H3N–BH3) as the hydrogen source and commercially available RuCl3·xH2O precatalyst for selective aromatic reduction of quinolines, quinoxalines, pyridines, pyrazines, indoles, benzofurans, furan derivatives to form corresponding alicyclic heterocycles in good excellent isolated yields. Applications straightforward include efficient preparation useful key pharmaceutical intermediates, such donepezil flumequine, including biologically active compound.

Язык: Английский

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Nickel-catalysed alkylation of C(sp³)–H bonds with alcohols: direct access to functionalised N-heteroaromatics

Chemical Communications, Год журнала: 2018, Номер 54(87), С. 12369 - 12372

Опубликована: Янв. 1, 2018

The first base-metal catalysed coupling of primary alcohols with methyl-N-heteroaromatics is reported. use an earth abundant and nonprecious NiBr2/L1 system enables access to a series C(sp3)-alkylated N-heteroaromatics. Mechanistic studies have established the participation hydrogen-borrowing strategy for α-alkylation.

Язык: Английский

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