Transition-Metal-Catalyzed Reductive Amination Employing Hydrogen

Chemical Reviews, Год журнала: 2020, Номер 120(17), С. 9583 - 9674

Опубликована: Авг. 19, 2020

The reductive amination, the reaction of an aldehyde or a ketone with ammonia amine in presence reducing agent and often catalyst, is important synthesis has been intensively investigated academia industry for century. Besides aldehydes, ketones, amines, starting materials have used that can be converted into (for instance, carboxylic acids organic carbonate nitriles) nitro compound) same catalyst. Mechanistically, starts condensation step during which carbonyl compound reacts amine, forming corresponding imine followed by reduction to alkyl product. Many these steps require catalyst activate agent. amination impressive regard product scope since primary, secondary, tertiary amines are accessible hydrogen most attractive agent, especially if large-scale formation issue, inexpensive abundantly available. Alkyl produced use fine bulk chemicals. They key functional groups many pharmaceuticals, agro chemicals, materials. In this review, we summarize work published on employing as No comprehensive review focusing subject 1948, albeit interesting summaries dealing one other aspect appeared. Impressive progress using catalysts based earth-abundant metals, nanostructured heterogeneous catalysts, made early development field recent years.

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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Development of a practical non-noble metal catalyst for hydrogenation of N-heteroarenes

Nature Catalysis, Год журнала: 2020, Номер 3(2), С. 135 - 142

Опубликована: Янв. 6, 2020

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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Asymmetric hydrogenation of ketimines with minimally different alkyl groups

Nature, Год журнала: 2024, Номер 631(8021), С. 556 - 562

Опубликована: Май 28, 2024

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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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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Manganese‐Catalyzed β‐Methylation of Alcohols by Methanol

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(4), С. 1485 - 1490

Опубликована: Ноя. 19, 2019

Abstract We report an earth‐abundant‐metal‐catalyzed double and single methylation of alcohols. A manganese catalyst, which operates at low catalyst loadings short reaction times, mediates these reactions efficiently. broad scope primary secondary alcohols, including purely aliphatic examples, 1,2‐aminoalcohols can be methylated. Furthermore, alcohol for the synthesis pharmaceuticals has been demonstrated. The system tolerates many functional groups among them hydrogenation‐sensitive examples upscaling is easily achieved. Mechanistic investigations are indicative a borrowing hydrogen or autotransfer mechanism involving bimetallic K‐Mn catalyst. accepts as proton hydride from alcohols efficiently reacts with chalcone via transfer.

Язык: Английский

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