Homogeneous and heterogeneous catalysts for hydrogenation of CO₂ to methanol under mild conditions

Chemical Society Reviews, Год журнала: 2021, Номер 50(7), С. 4259 - 4298

Опубликована: Янв. 1, 2021

This review summarizes the concepts, mechanisms, drawbacks and challenges of state-of-the-art catalysis for CO₂ to MeOH under mild conditions. Thoughtful guidelines principles future research are presented discussed.

Язык: Английский

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Homogeneous manganese-catalyzed hydrogenation and dehydrogenation reactions

Chem, Год журнала: 2020, Номер 7(5), С. 1180 - 1223

Опубликована: Дек. 9, 2020

Язык: 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, Год журнала: 2022, Номер 7(5), С. 438 - 447

Опубликована: Май 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.

Язык: Английский

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Manganese-catalyzed hydrogenation, dehydrogenation, and hydroelementation reactions

Chemical Society Reviews, Год журнала: 2022, Номер 51(11), С. 4386 - 4464

Опубликована: Янв. 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.

Язык: Английский

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

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Янв. 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.

Язык: Английский

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Homogeneous Hydrogenation of CO₂ and CO to Methanol: The Renaissance of Low‐Temperature Catalysis in the Context of the Methanol Economy

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(42)

Опубликована: Авг. 3, 2022

The traditional economy based on carbon-intensive fuels and materials has led to an exponential rise in anthropogenic CO

Язык: Английский

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Manganese‐Catalyzed Asymmetric Hydrogenation of Quinolines Enabled by π–π Interaction**

Angewandte Chemie International Edition, Год журнала: 2020, Номер 60(10), С. 5108 - 5113

Опубликована: Ноя. 26, 2020

Abstract The non‐noble metal‐catalyzed asymmetric hydrogenation of N‐heteroaromatics, quinolines, is reported. A new chiral pincer manganese catalyst showed outstanding catalytic activity in the affording high yields and enantioselectivities (up to 97 % ee). turnover number 3840 was reached at a low loading (S/C=4000), which competitive with most effective noble metal catalysts for this reaction. precise regulation enantioselectivity were ensured by π–π interaction.

Язык: 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, Год журнала: 2019, Номер 141(29), С. 11677 - 11685

Опубликована: Июнь 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.

Язык: Английский

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Unmasking the Ligand Effect in Manganese-Catalyzed Hydrogenation: Mechanistic Insight and Catalytic Application

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(43), С. 17337 - 17349

Опубликована: Окт. 21, 2019

Manganese-catalyzed hydrogenation reactions have attracted broad interest since the first report in 2016. Among reported catalytic systems, Mn catalysts supported by tridentate PNP- and NNP-pincer ligands most commonly been used. For example, a number of PNP-Mn pincer for aldehydes, aldimines, ketones, nitriles, esters. Furthermore, various NNP-Mn shown to be active less-reactive substrates such as amides, carbonates, carbamates, urea derivations. These observations indicated that exhibit higher reactivity than their PNP counterparts. Such ligand effect Mn-catalyzed has yet confirmed. Herein, we investigated origin applicability this effect. A combination experimental theoretical investigations showed on complexes were more electron-rich less sterically hindered counterparts, leading series reactions. Inspired hydrogenations, developed N-heterocycles. Specifically, hydrogenated N-heterocycles (32 examples) with up 99% yields, corresponding afforded low under same conditions. This verified is generally applicable both carbonyl noncarbonyl based catalysis.

Язык: Английский

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Catalytic Hydrogenation of Cyclic Carbonates using Manganese Complexes

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(41), С. 13449 - 13453

Опубликована: Авг. 22, 2018

Catalytic hydrogenation of cyclic carbonates to diols and methanol was achieved using a molecular catalyst based on earth-abundant manganese. The complex [Mn(CO)

Язык: Английский

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