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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Homogeneous manganese-catalyzed hydrogenation and dehydrogenation reactions

Chem, Journal Year: 2020, Volume and Issue: 7(5), P. 1180 - 1223

Published: Dec. 9, 2020

Language: Английский

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Reversible hydrogenation of carbon dioxide to formic acid using a Mn-pincer complex in the presence of lysine

Nature Energy, Journal Year: 2022, Volume and Issue: 7(5), P. 438 - 447

Published: May 19, 2022

Abstract Efficient hydrogen storage and release are essential for effective use of as an energy carrier. In principle, formic acid could be used a convenient medium via reversible CO 2 hydrogenation. However, noble metal-based catalysts currently needed to facilitate the (de)hydrogenation, produced during is generally released, resulting in undesirable emissions. Here we report α -amino acid-promoted system hydrogenation using Mn-pincer complex homogeneous catalyst. We observe good stability reusability catalyst lysine amino at high productivities (CO hydrogenation: total turnover number 2,000,000; dehydrogenation: 600,000). Employing potassium lysinate, achieve >80% H evolution efficiency >99.9% retention ten charge–discharge cycles, avoiding re-loading steps between each cycle. This process was scaled up by factor 18 without obvious drop productivity.

Language: Английский

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Manganese-catalyzed hydrogenation, dehydrogenation, and hydroelementation reactions

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(11), P. 4386 - 4464

Published: Jan. 1, 2022

The emerging field of organometallic catalysis has shifted towards research on Earth-abundant transition metals due to their ready availability, economic advantage, and novel properties. In this case, manganese, the third most abundant transition-metal in Earth's crust, emerged as one leading competitors. Accordingly, a large number molecularly-defined Mn-complexes been synthesized employed for hydrogenation, dehydrogenation, hydroelementation reactions. regard, catalyst design is based three pillars, namely, metal-ligand bifunctionality, ligand hemilability, redox activity. Indeed, developed catalysts not only differ chelating atoms they possess but also working principles, thereby different turnover numbers product molecules. Hence, critical assessment molecularly defined manganese terms atoms, reaction conditions, mechanistic pathway, significant. Herein, we analyze complexes catalytic activity, versatility allow multiple transformations routes convert substrates target This article will be helpful get significant insight into design, aiding design.

Language: Английский

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Robust and efficient hydrogenation of carbonyl compounds catalysed by mixed donor Mn(I) pincer complexes

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Jan. 4, 2021

Abstract Any catalyst should be efficient and stable to implemented in practice. This requirement is particularly valid for manganese hydrogenation catalysts. While representing a more sustainable alternative conventional noble metal-based systems, catalysts are prone degrade under catalytic conditions once operation temperatures high. Herein, we report highly Mn(I)-CNP pre-catalyst which gives rise the excellent productivity (TOF° up 41 000 h −1 ) stability (TON 200 000) catalysis. system enables near-quantitative of ketones, imines, aldehydes formate esters at loadings as low 5–200 p.p.m. Our analysis points crucial role activation step performance system. employing alkoxide bases can ultimately provide catalytically competent species hydrogen atmosphere, Mn(I) with hydride donor promoters, e.g. KHBEt 3 , dramatically improves eliminates induction times associated slow activation.

Language: Английский

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Homogeneously catalyzed acceptorless dehydrogenation of alcohols: A progress report

Coordination Chemistry Reviews, Journal Year: 2021, Volume and Issue: 443, P. 213967 - 213967

Published: May 24, 2021

Catalytic dehydrogenation of alcohols represents an attractive approach for future applications as hydrogen storage systems and clean synthesis fine chemicals. Herein, overview recent progress in homogeneously catalyzed acceptorless alcohol is presented. In Nature, efficiently by multiple metalloenzymes where a non-noble metal–ligand interplay key to activate transform substrate. We highlight the introduction multifunctional cooperative ligands coordination sphere metal center order improve catalytic activity under photochemical, electrochemical or thermal conditions. Moreover, cooperativity crucial easy transition first row based catalysis, we have seen years.

Language: Английский

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Borrowing Hydrogen Amination Reactions: A Complex Analysis of Trends and Correlations of the Various Reaction Parameters

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(12), P. 7142 - 7198

Published: June 1, 2022

Borrowing hydrogen or the autotransfer amination is a powerful approach to create single C–N bonds, starting from stable and readily available substrates: amines alcohols. It considered as one of most atom-efficient green methods synthesize complex amines. Herein, we attempted arrange array existing data in comprehensive structured manner determine correlations between experimental conditions catalysis outcome both within different groups catalysts defined using machine analysis. For each type N-nucleophiles (aromatic, aliphatic, heteroaromatic amines, amides), efficient working were suggested, including attributing optimal base temperature regime for metal.

Language: Английский

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Room temperature N-heterocyclic carbene manganese catalyzed selective N-alkylation of anilines with alcohols

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(44), P. 6213 - 6216

Published: Jan. 1, 2019

The first example of room temperature non-noble metal homogeneous system catalyzed selective N-alkylation anilines with alcohols by a bis-NHC manganese complex is presented. This was applied to large range and anilines, including biologically relevant motifs challenging methanol. Experimental computational studies suggest an outer-sphere mechanism for this NHC-Mn system.

Language: Английский

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Mechanistic Studies of Hydride Transfer to Imines from a Highly Active and Chemoselective Manganate Catalyst

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(29), P. 11677 - 11685

Published: June 28, 2019

We introduce a highly active and chemoselective manganese catalyst for the hydrogenation of imines. The has large scope, can reduce aldimines ketimines, tolerates variety functional groups, among them sensitive examples such as an olefin, ketone, nitriles, nitro aryl iodo substituent or benzyl ether. could investigate transfer step between imines hydride complex in detail. found that double deprotonation ligand is essential excess base does not lead to higher rate step. identified actual K–Mn-bimetallic species obtain structure K–Mn formed after by X-ray analysis. NMR experiments indicate well-defined reaction, which first order imine, bimetallic (K–Mn) hydride, independent from concentration potassium base. propose outer-sphere mechanism protons do seem be involved rate-determining step, leading transiently negatively charged nitrogen atom substrate reacts rapidly with HOtBu (2-methylpropan-2-ol) produce amine. This based on several observations, no dependency reaction concentration, observable amide complex, high constant conducted Hammett study. Furthermore, hydrogen catalytic cycle was experimentally probed monitored subsequent quantitative regeneration H2.

Language: Английский

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Cycloamination strategies for renewable N-heterocycles

Green Chemistry, Journal Year: 2020, Volume and Issue: 22(3), P. 582 - 611

Published: Jan. 1, 2020

Efficient amination strategies for synthesis of N-heterocycles from functional molecules (bottom-up) or biomass (top-down) via sustainable C–N/C–X bond chemistry.

Language: Английский

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