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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The transition metal-catalysed hydroboration reaction

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(21), P. 8877 - 8922

Published: Jan. 1, 2022

This review covers the development of transition metal-catalysed hydroboration reaction, from its beginnings in 1980s to more recent developments including earth-abundant catalysts and an ever-expanding array substrates.

Language: Английский

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Ir-Catalyzed Regioselective Dihydroboration of Thioalkynes toward Gem-Diboryl Thioethers

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(4), P. 2305 - 2314

Published: Jan. 19, 2023

While 1,1-diboryl (gem-diboryl) compounds are valuable synthetic building blocks, currently, related studies have mainly focused on those alkanes without a hetero functional group in the α-position. gem-Diboryl with an α-hetero substituent, though highly versatile, been limitedly accessible and thus rarely utilized. Herein, we developed first α-dihydroboration of heteroalkynes leading to efficient construction gem-diboryl, hetero-, tetra-substituted carbon centers. This straightforward, practical, mild, atom-economic reaction is attractive complement conventional multistep strategy relying deprotonation gem-diborylmethane by strong base. Specifically, [Ir(cod)(OMe)]2 was found be uniquely effective for this process thioalkynes, excellent α-regioselectivity when delivering two boryl groups, which remarkable view many competitive paths including monohydroboration, 1,2-dihydroboration, dehydrodiboration, triboration, tetraboration, etc. Control experiments combined DFT calculations suggested that involves sequential hydroboration events. The second requires higher energy barrier due severe steric repulsion generating congested α-sulfenyl gem-diboryl center, structural motif almost unknown before.

Language: Английский

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Manganese-Catalyzed Dehydrogenative Silylation of Alkenes Following Two Parallel Inner-Sphere Pathways

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(42), P. 17825 - 17832

Published: Oct. 13, 2021

We report on an additive-free Mn(I)-catalyzed dehydrogenative silylation of terminal alkenes. The most active precatalyst is the bench-stable alkyl bisphosphine Mn(I) complex fac-[Mn(dippe)(CO)3(CH2CH2CH3)]. catalytic process initiated by migratory insertion a CO ligand into Mn–alkyl bond to yield acyl intermediate which undergoes rapid Si–H cleavage silane HSiR3 forming 16e– silyl catalyst [Mn(dippe)(CO)2(SiR3)] together with liberated butanal. A broad variety aromatic and aliphatic alkenes was efficiently selectively converted E-vinylsilanes allylsilanes, respectively, at room temperature. Mechanistic insights are provided based experimental data DFT calculations revealing that two parallel reaction pathways operative: acceptorless pathway involving dihydrogen release requiring alkene as sacrificial hydrogen acceptor.

Language: Английский

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E-Selective Manganese-Catalyzed Semihydrogenation of Alkynes with H₂ Directly Employed or In Situ-Generated

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(4), P. 2253 - 2260

Published: Jan. 31, 2022

Selective semihydrogenation of alkynes with the Mn(I) alkyl catalyst fac-[Mn(dippe)(CO)3(CH2CH2CH3)] (dippe = 1,2-bis(di-iso-propylphosphino)ethane) as a precatalyst is described. The required hydrogen gas either directly employed or in situ-generated upon alcoholysis KBH4 methanol. A series aryl-aryl, aryl-alkyl, alkyl-alkyl, and terminal was readily hydrogenated to yield E-alkenes good excellent isolated yields. reaction proceeds at 60 °C for 60-90 loadings 0.5-2 mol %. implemented protocol tolerates variety electron-donating electron-withdrawing functional groups, including halides, phenols, nitriles, unprotected amines, heterocycles. can be upscaled gram scale. Mechanistic investigations, deuterium-labeling studies density theory (DFT) calculations, were undertaken provide reasonable mechanism, showing that initially formed Z-isomer undergoes fast isomerization afford thermodynamically more stable E-isomer.

Language: Английский

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Manganese Alkyl Carbonyl Complexes: From Iconic Stoichiometric Textbook Reactions to Catalytic Applications

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(18), P. 2740 - 2751

Published: Sept. 8, 2022

ConspectusThe activation of weakly polarized bonds represents a challenging, yet highly valuable process. In this context, precious metal catalysts have been used as reliable compounds for the rather inert last several decades. Nevertheless, base-metal complexes including cobalt, iron, or nickel are currently promising candidates substitution noble metals in order to develop more sustainable processes. past few years, manganese(I)-based were heavily employed efficient (de)hydrogenation reactions. However, vast majority these operate via metal–ligand bifunctionality already well implemented decades ago. Although high reactivity can be achieved various reactions, concept is often not applicable certain transformations due outer-sphere mechanisms. Account, we outline potential alkylated Mn(I)-carbonyl nonpolar and moderately polar E–H (E = H, B, C, Si) disclose our successful approach utilization field homogeneous catalysis. This involves rational design manganese hydrogenation reactions involving ketones, nitriles, carbon dioxide, alkynes. addition that, reduction alkenes by dihydrogen could series well-defined which was possible before. Furthermore, elucidate Mn-based hydrofunctionalization carbon–carbon multiple bonds. Our investigations unveiled novel insights into reaction pathways dehydrogenative silylation trans-1,2-diboration terminal alkynes, reported transition metals. Due catalyst design, under mild conditions. Delightfully, all bench-stable compounds. We took advantage fact that Mn(I) alkyl known undergo migratory insertion group CO ligand, yielding an unsaturated acyl intermediate. Hydrogen atom abstraction ligand then paves way active species variety catalytic proceed inner-sphere textbook well-known decades, application still its infancy. A brief historical overview manganese(I)–carbonyl provided, covering synthesis especially iconic stoichiometric transformations, e.g., carbonylation, intensively examined Calderazzo, Moss, others. An future applications defined will given, may inspire researchers development (base-)metal catalysts.

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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Homogeneous Manganese-Catalyzed Hydrofunctionalizations of Alkenes and Alkynes: Catalytic and Mechanistic Tendencies

ACS Omega, Journal Year: 2022, Volume and Issue: 7(42), P. 37008 - 37038

Published: Oct. 11, 2022

In recent years, many manganese-based homogeneous catalytic precursors have been developed as powerful alternatives in organic synthesis. Among these, the hydrofunctionalizations of unsaturated C–C bonds correspond to outstanding ways afford compounds with more versatile functional groups, which are commonly used building blocks production fine chemicals and feedstock for industrial field. Herein, we present an account Mn-catalyzed alkenes alkynes main objective finding mechanistic tendencies that could serve a platform works come.

Language: Английский

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Stabilizing Single‐Atomic Pt by Forming PtFe Bonds for Efficient Diboration of Alkynes

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(14)

Published: Jan. 12, 2023

Precisely tailoring the oxidation state of single-atomic metal in heterogeneous catalysis is an efficient way to stabilize site and promote their activity, but realizing this approach remains a grand challenge date. Herein, class stable catalysts with well-tuned Pt by forming PtFe atomic bonds reported, which are supported defective Fe2 O3 nanosheets on reduced graphene oxide (PFARFNs). These as-synthesized materials can greatly enhance catalytic stability, selectivity for diboration alkynes. The PFARFNs exhibit high conversion 99% at 100 °C outstanding turnover frequency (TOF) 545 h-1 , relatively 58% room temperature (25 °C) TOF 310 has been hardly achieved previously. Through both experimental theoretical investigation, it demonstrated that fast electron transfer from Fe Fe-Pt-O sites not only Pt, also significantly improve activity.

Language: Английский

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Cobalt-catalyzed dehydrogenative cross-coupling reaction: Selective access to dihydrosiloxanes, hydrosiloxanes and functionalized silsesquioxanes

Journal of Catalysis, Journal Year: 2023, Volume and Issue: 423, P. 1 - 9

Published: April 27, 2023

Disclosed is a mild, scalable, and chemoselective cross-dehydrogenative functionalization protocol for the construction of Si−O−Si moieties under cobalt catalysis. The reaction has broad scope can be used to synthesize wide range silicon building blocks, including challenging dihydrosiloxanes functionalized silsesquioxanes. Most importantly, results are placed into context by benchmarking with state-of-the-art methods. Remarkably, utilized PNP-Co catalyst enables development further synthetic strategies such as one-pot sequential silanolysis/alcoholysis process or unprecedented dehydrocoupling between germanol hydrosilane.

Language: Английский

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