CrCl₂-catalyzed α-alkylation of carbonyl compounds via a borrowing hydrogen approach

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(7), С. 1955 - 1962

Опубликована: Янв. 1, 2024

A new and efficient catalytic system for sustainable α-alkylation of carbonyl compounds with alcohols via a borrowing hydrogen strategy is presented.

Язык: Английский

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A Proton‐Responsive Pyridyl(benzamide)‐Functionalized NHC Ligand on Ir Complex for Alkylation of Ketones and Secondary Alcohols

Chemistry - A European Journal, Год журнала: 2021, Номер 27(41), С. 10737 - 10748

Опубликована: Май 17, 2021

Abstract A Cp*Ir(III) complex ( 1 ) of a newly designed ligand L featuring proton‐responsive pyridyl(benzamide) appended on N ‐ heterocyclic carbene (NHC) has been synthesized. The molecular structure reveals dearomatized form the ligand. protonation with HBF 4 in tetrahydrofuran gives corresponding aromatized [Cp*Ir(L H)Cl]BF 2 ). Both compounds are characterized spectroscopically and by X‐ray crystallography. acid is examined H NMR UV‐vis spectra. character exploited for catalyzing α ‐alkylation ketones β secondary alcohols using primary as alkylating agents through hydrogen‐borrowing methodology. Compound an effective catalyst these reactions exhibits superior activity comparison to structurally similar iridium )Cl]PF 6 3 lacking pendant amide moiety. catalytic alkylation wide substrate scope, low base loadings, short reaction time. efficacy also demonstrated syntheses quinoline lactone derivatives via acceptorless dehydrogenation, selective two steroids, pregnenolone testosterone. Detailed mechanistic investigations DFT calculations substantiate role process.

Язык: Английский

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Well‐Defined Ni−SNS Complex Catalysed Borrowing Hydrogenative α‐Alkylation of Ketones and Dehydrogenative Synthesis of Quinolines

Advanced Synthesis & Catalysis, Год журнала: 2022, Номер 364(14), С. 2429 - 2437

Опубликована: Май 23, 2022

Abstract The “borrowing hydrogen” (BH) method for C‐alkylation reactions using alcohol as alkylating agents is an important synthetic transformation. In this respect, designing cheap and bench stable earth abundant metal catalyst borrowing hydrogen transformation a key challenge to be witnessed. Herein we have presented synthesis of non‐phosphine, easily accessible SNS−Ni complexes. Ni‐catalyst was successfully applied the ketone enolates α‐alkylated ketones. Primary with different functional groups various heteroaromatic alcohols are well tolerated. present system efficiently gram scale also green chemistry metrics reaction were calculated. protocol extended biologically quinoline moieties. Finally, control experiments deuterium labelled suggest that proceeds via pathway. magnified image

Язык: Английский

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Atomically Dispersed Co on N-Doped Porous Carbon for the Highly Efficient Catalytic Oxidation of Aromatic Alcohols to Acids and Nitriles

ACS Catalysis, Год журнала: 2023, Номер 13(24), С. 16286 - 16299

Опубликована: Дек. 6, 2023

An ecofriendly and facile strategy for converting aromatic alcohols to high-value-added compounds, especially acids nitriles, is highly desirable. Herein, atomically dispersed Co species anchored on N-doped porous carbon were fabricated by simple one-pot pyrolysis using low-cost precursors. The as-obtained Co/NC catalyst with a high loading of 8.77 wt % exhibited excellent performance the one-step oxidation alcohols. Under ambient air reaction conditions addition KOH or NH3·H2O, successfully converted corresponding respectively. Experimental theoretical studies confirmed that Co–N4 sites serve as primary active activation transformation aldehydes crucial intermediate pathway. Density functional theory (DFT) calculations revealed compared nanoparticle catalysts, lower energy barrier aerobic benzyl alcohol benzaldehyde. Additionally, prepared single-atom displayed remarkable recyclability applicability. This study provides not only potential constructing efficient non-noble metal catalysts but also approach products.

Язык: Английский

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Selective Transfer Hydrogenation of C=O and Conjugated C=C Bonds Using An NHC‐Based Pincer (CNC)Mn^I Complex in Methanol**

ChemSusChem, Год журнала: 2023, Номер 16(18)

Опубликована: Июнь 8, 2023

Base metal catalyzed transfer hydrogenation reactions using methanol is highly challenging. Employing a single N-heterocyclic carbene (NHC)-based pincer (CNC)MnI complex, chemoselective and double of α, β-unsaturated ketones to saturated or alcohols by utilizing as the hydrogen source disclosed. The protocol was tolerant towards selective C=C C=O bonds in presence several other reducible functional groups led synthesis biologically relevant molecules natural products. Notably, this first report Mn-catalyzed carbonyl with methanol. Several control experiments, kinetic studies, Hammett density theory (DFT) calculations were carried out understand mechanistic details catalytic process.

Язык: Английский

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Hydrogenation of Carboxylic Esters Catalyzed by Phosphine-Free Bis-N-heterocyclic Carbene Manganese Complexes

Organometallics, Год журнала: 2023, Номер 42(14), С. 1832 - 1838

Опубликована: Июнь 5, 2023

As an earth-abundant transition metal, manganese is now recognized as a good candidate for the development of catalysts reduction-type reactions. It often associated with noninnocent tridentate ligand, featuring acidic NH moiety. We report here that simple bidentate and phosphine-free bis-N-heterocyclic ligand in complex [Mn(bis-NHCMes)(CO)3Br] could catalyze hydrogenation carboxylic esters presence KBHEt3 activator at 100–120 °C under 50 bar H2 1 mol % catalyst loading 2-Me-THF.

Язык: Английский

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Recent advances on N-heterocyclic carbene transition metal complexes for dehydrogenative catalysis using alcohols

Catalysis Today, Год журнала: 2020, Номер 370, С. 114 - 141

Опубликована: Окт. 20, 2020

Язык: Английский

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Nickel‐Catalyzed Selective Synthesis of α‐Alkylated Ketones via Dehydrogenative Cross‐Coupling of Primary and Secondary Alcohols

Advanced Synthesis & Catalysis, Год журнала: 2021, Номер 364(1), С. 47 - 52

Опубликована: Окт. 11, 2021

Abstract Herein, we describe an isolable, air‐stable, homogeneous, nickel catalyst that performs dehydrogenative cross‐coupling reaction between secondary and primary alcohols to result α‐alkylated ketone products selectively. The sequence of steps involve in this one‐pot is dehydrogenation both alcohols, condensation the aldehyde, hydrogenation situ‐generated α,β‐unsaturated ketone. Preliminary mechanistic investigation hints a radical mechanism following borrowing hydrogen reaction. magnified image

Язык: Английский

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Recent advances in C/N-alkylation with alcohols through hydride transfer strategies

Organic & Biomolecular Chemistry, Год журнала: 2022, Номер 20(39), С. 7713 - 7745

Опубликована: Янв. 1, 2022

Recent advances in C/N alkylation using alcohols as alkylating reagents via hydrogen-shuttle methodologies: Borrowing Hydrogen, Acceptorless Dehydrogenative Coupling, and Base-mediated Hydride Transfer.

Язык: Английский

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N‐Heterocyclic and Mesoionic Carbenes of Manganese and Rhenium in Catalysis

European Journal of Inorganic Chemistry, Год журнала: 2022, Номер 2022(10)

Опубликована: Янв. 11, 2022

Abstract The use of N‐heterocyclic carbenes (NHCs) in manganese and rhenium catalysis is underdeveloped comparison to other transition metals. Herein, we cover the recent stimulating progress homogeneous using Mn‐NHC complexes, namely hydrosilylation, hydrogenation, borrowing hydrogen processes. Of particular interest application Mn Re NHC catalysts electrochemical photochemical reduction CO 2 .

Язык: Английский

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