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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Cobalt-catalyzed synthesis of amides from alkenes and amines promoted by light

Science, Journal Year: 2024, Volume and Issue: 383(6678), P. 77 - 81

Published: Jan. 4, 2024

Catalytic methods to couple alkene and amine feedstocks are valuable in synthetic chemistry. The direct carbonylative coupling of alkenes amines holds promise as a perfectly atom-economical approach amide synthesis, but general remain underdeveloped. Herein, we report an hydroaminocarbonylation catalyzed by unmodified, inexpensive cobalt carbonyl under mild conditions low pressure promoted light. Silane addition after the reaction enables sequential cobalt-catalyzed reduction, constituting formal hydroaminomethylation. These exhibit exceptional scope across both components with high chemo- regioselectivity proceed efficiently even absence solvent. formation hydridocobalt through photodissociation ligand is proposed enable catalytic activity conditions, which addresses long-standing challenge catalysis.

Language: Английский

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Towards ligand simplification in manganese-catalyzed hydrogenation and hydrosilylation processes

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 458, P. 214421 - 214421

Published: Jan. 31, 2022

Language: Английский

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The Rise of Manganese-Catalyzed Reduction Reactions

Synthesis, Journal Year: 2021, Volume and Issue: 54(03), P. 517 - 534

Published: Sept. 29, 2021

Abstract Recent developments in manganese-catalyzed reducing transformations—hydrosilylation, hydroboration, hydrogenation, and transfer hydrogenation—are reviewed herein. Over the past half a decade (i.e., 2016 to present), more than 115 research publications have been reported these fields. Novel organometallic compounds new reduction transformations discovered further developed. Significant challenges that had historically acted as barriers for use of manganese catalysts reactions are slowly being broken down. This review will hopefully assist developing this area, by presenting clear concise overview catalyst structures substrate published so far. 1 Introduction 2 Hydrosilylation 3 Hydroboration 4 Hydrogenation 5 Transfer 6 Conclusion Perspective

Language: Английский

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A Safer Reduction of Carboxylic Acids with Titanium Catalysis

Organic Letters, Journal Year: 2022, Volume and Issue: 24(46), P. 8481 - 8486

Published: Nov. 15, 2022

Ammonia-borane, shown previously to react with carboxylic acids under reflux form primary amides, reduces alcohols at room temperature in the presence of catalytic TiCl4. The process, which is tolerant a variety potentially reactive functional groups, including N-protected amino acids, can be employed for selective reduction nitriles and, some extent, esters. Aliphatic selectively reduced aromatic acids.

Language: Английский

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Manganese-Catalyzed Chemoselective Hydrosilylation of Nitroarenes: Sustainable Route to Aromatic Amines

Organic Letters, Journal Year: 2022, Volume and Issue: 24(50), P. 9179 - 9183

Published: Nov. 22, 2022

Herein we report efficient catalytic hydrosilylations of nitroarenes to form the corresponding aromatic amines using a well-defined manganese(II)-NNO pincer complex with low catalyst loading (1 mol %) under solvent-free conditions. This base-metal-catalyzed hydrosilylation is an easy and sustainable alternative classical hydrogenation. A large variety bearing various functionalities were selectively transformed into in good yields. The potential utility present protocol was demonstrated by preparation commercial drug molecules.

Language: Английский

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Titanium‐Catalyzed Exhaustive Reduction of Oxo‐Chemicals

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(46)

Published: Sept. 20, 2022

Catalytic reduction of carboxylic acids and derivatives all the way to their corresponding methyl-compounds is very rare still challenging for homogeneous transition-metal catalysis. Herein, we report an unprecedented general catalytic exhaustive functional group straightforwardly a methyl group. This reaction was achieved using earth-abundant readily available titanium as catalyst. Our system has broad tolerance works various other types oxo-chemicals such alcohols, aldehydes, ketones, lactones, carboxylates (>100 examples). Preliminary mechanistic studies revealed that in situ-generated TiIII -H species vital this transformation.

Language: Английский

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Silica-Immobilized Cyclic Urea Catalyst for the Reduction of Carboxylic Acids to Alcohols

JACS Au, Journal Year: 2025, Volume and Issue: unknown

Published: March 17, 2025

Catalytic reduction of carboxylic acids to the corresponding alcohols is a challenging but useful reaction. Since conventional methods such as hydrogenation and hydrosilylation largely rely on transition-metal catalysts, development heterogeneous organocatalysts for reaction an attractive research target. In this study, we achieved benzoic acid derivatives benzylic by with silica-immobilized cyclic urea catalyst followed hydrolysis. The catalytic activity immobilized was significantly higher than that free urea, silica supports, their physical mixture, or different structures, carbonates amines. Control experiments Fourier transform infrared (FT-IR) spectroscopy revealed synergy between silanol groups surface resulted in superior catalysis silyl ester intermediate key step. It proposed concertedly activate hydrosilane ester, respectively, achieve efficient hydride transfer, which supported density functional theory (DFT) calculations model systems. This study demonstrates concerted activation nucleophiles electrophiles effective molecular transformations.

Language: Английский

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Facile, green, and functional group-tolerant reductions of carboxylic acids…in, or with, water

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(7), P. 2663 - 2671

Published: Jan. 1, 2023

Facile reductions of carboxylic acids to aldehydes or alcohols can be effected under mild conditions upon initial conversion their corresponding S -2-pyridyl thioesters.

Language: Английский

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Silyl Esters as Reactive Intermediates in Organic Synthesis

Synthesis, Journal Year: 2023, Volume and Issue: 55(20), P. 3209 - 3238

Published: April 28, 2023

Abstract Silyl esters have been exploited as metastable reaction intermediates, both purposefully and unintentionally, since at least the 1960s. Their reactivity is broadly related to substituents on silicon, in this way their properties can be readily modulated. unique profiles that used generate downstream products of a range functionalities, because many excellent methods for synthesis variety value-added chemicals developed. Furthermore, frequent use hydrosilanes terminal reductants catalytic processes, silyl ester intermediates are likely more commonly utilized by synthetic chemists than currently realized. This review comprehensively summarizes reactions known take advantage reactive discusses examples proceed an unanticipated manner through intermediates. 1 Introduction 2 Synthesis Esters 3 Making Amides from 3.1 Amidation Using Chlorosilanes 3.2 Azasilanes 3.3 Oxysilanes 3.4 Hydrosilanes 3.5 Amine Formation via Amidation/Reduction 3.6 Miscellaneous 4 Mechanistic Investigations 4.1 Mechanism 4.2 4.3 Oxy- or 5 6 Aldehydes, Alcohols, Amines, Alkanes Reduction 6.1 Aldehyde Metal-Free 6.2 Metal-Mediated 6.3 Alcohol 6.4 6.5 Alkane 7 Acid Chlorides 8 In Situ Generated Ramifications Catalysis 9 Conclusion

Language: Английский

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