Hydrogenation of Terminal Alkenes Catalyzed by Air‐Stable Mn(I) Complexes Bearing an N‐Heterocyclic Carbene‐Based PCP Pincer Ligand

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 30(4)

Published: Oct. 10, 2023

Efficient hydrogenations of terminal alkenes with molecular hydrogen catalyzed by well-defined bench stable Mn(I) complexes containing an N-heterocyclic carbene-based PCP pincer ligand are described. These reactions environmentally benign and atom economic, implementing inexpensive, earth abundant non-precious metal catalyst. A range aromatic aliphatic were efficiently converted into alkanes in good to excellent yields. The hydrogenation proceeds at 100 °C catalyst loadings 0.25-0.5 mol %, 2.5-5 % base (KO

Language: Английский

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Thioether–NHC bidentate manganese complexes as efficient phosphine-free catalysts for hydrogenation at room temperature

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A series of four original phosphine-free thioether-NHC manganese complexes have been synthesised and fully characterized. These applied as efficient catalysts for the hydrogenation alkenes ketones at room temperature, with low catalyst loadings (TON up to 900).

Language: Английский

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Renaissance in Alkyne Semihydrogenation: Mechanism, Selectivity, Functional Group Tolerance, and Applications in Organic Synthesis

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: April 25, 2025

Alkenes constitute a significant class of chemical compounds with applications in the bulk, pharmaceutical, or perfume industry. Among known methods olefin production, semihydrogenation C-C triple bond seems to be most straightforward one. Nonetheless, success this reaction requires full control over diastereoselectivity, eradication parasitic process over-reduction migration double formed, and achieving satisfactory functional-group compatibility. The review demonstrates developments field alkyne period 2010-2022, selected papers published 2023 2024, emphasizing solutions above-mentioned limitations. We discuss mechanistic aspects transformation, including those related unconventional systems. includes examples organic synthesis, confirming considerable utility process. Finally, strategies enhance catalyst selectivity are summarized. For reader's convenience, we provided graphical guidebook catalytic systems, illustrating efficiency particular method.

Language: Английский

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Homogeneous Catalytic Hydrogenation of C=C and C≡C

Elsevier eBooks, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Language: Английский

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Selective Transfer Semihydrogenation of Alkynes Catalyzed by an Iron PCP Pincer Alkyl Complex

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(21), P. 14012 - 14022

Published: Oct. 17, 2023

Two bench-stable Fe(II) alkyl complexes [Fe(κ3PCP-PCP-iPr)(CO)2(R)] (R = CH2CH2CH3, CH3) were obtained by the treatment of [Fe(κ3PCP-PCP-iPr)(CO)2(H)] with NaNH2 and subsequent addition CH3CH2CH2Br CH3I, respectively. The reaction proceeds via anionic Fe(0) intermediate Na[Fe(κ3PCP-PCP-iPr)(CO)2]. catalytic performance both was investigated for transfer hydrogenation terminal internal alkynes utilizing PhSiH3 iPrOH as a hydrogen source. Precatalyst activation is initiated migration ligand to carbonyl C atom an adjacent CO ligand. In agreement previous findings, rate follows order nPr > Me. Accordingly, [Fe(κ3PCP-PCP-iPr)(CO)2(CH2CH2CH3)] more active catalyst. takes place at 25 °C catalyst loading 0.5 mol%. There no overhydrogenation, in case alkynes, exclusively, Z-alkenes are formed. implemented protocol tolerates variety electron-donating electron-withdrawing functional groups including halides, nitriles, unprotected amines, heterocycles. Mechanistic investigations deuterium labeling studies DFT calculations undertaken provide reasonable mechanism.

Language: Английский

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Hydrogenation of carboxylic esters catalyzed by manganese catalysts supported by bidentate NHC-phosphine ligands

Journal of Catalysis, Journal Year: 2024, Volume and Issue: 430, P. 115334 - 115334

Published: Jan. 27, 2024

Language: Английский

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Tandem manganese catalysis for the chemo-, regio-, and stereoselective hydroboration of terminal alkynes: in situ precatalyst activation as a key to enhanced chemoselectivity

RSC Advances, Journal Year: 2024, Volume and Issue: 14(8), P. 5514 - 5523

Published: Jan. 1, 2024

The manganese( ii ) complex [Mn( iPr PNP)Cl 2 ] ( PNP = 2,6-bis(diisopropylphosphinomethyl)pyridine) was found to catalyze the stereo- and regioselective hydroboration of terminal alkynes employing HBPin (pinacolborane).

Language: Английский

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Designing a Green Replacement for the Lindlar Catalyst for Alkyne Semi-hydrogenation Using Silica-Supported Nickel Nanoparticles Modified by N-Doped Carbon

ACS Sustainable Chemistry & Engineering, Journal Year: 2022, Volume and Issue: 10(30), P. 9787 - 9797

Published: July 21, 2022

A lead- and palladium-free alternative to the Lindlar catalyst has been developed for industrially relevant alkyne semi-hydrogenation using silica-supported nickel nanoparticles modified by nitrogen-doped carbon. The optimal acts under mild conditions (5 bar H2, 100 °C, 4 h) selective of a range alkynes, including vitamin precursors that are important food supplements. Notably, this novel is alkynes in presence easily reducible groups such as carbonyl nitrile, which also makes it attractive other synthetic applications.

Language: Английский

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Ligand-to-metal ratio controls stereoselectivity: Highly functional-group-tolerant, iridium-based, (E)-selective alkyne transfer semihydrogenation

Chem Catalysis, Journal Year: 2022, Volume and Issue: 2(6), P. 1346 - 1361

Published: May 16, 2022

Herein, we present (E)-selective transfer semihydrogenation of alkynes based on an iridium complex in situ generated from [Ir(COD)Cl]2 and unsymmetrical (bearing two different phosphorous centers), ferrocene-based phosphine ligand utilizing formic acid as a hydrogen donor. Interestingly, ligand-to-metal ratio may be used to control the stereoselectivity process: 1:1 led formation (Z)-alkene major product, whereas 1:2 gave exclusively (E)-alkene. The latter catalytic system is distinguished by its unprecedented chemoselectivity exceptional stereoselectivity, which substantiated broad scope tested substrates, including natural product derivatives. intriguing difference activity between symmetrical ligands was attributed divergent coordination steric hindrance. presented methodology constitutes solution common limitations known systems for semihydrogenation.

Language: Английский

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Transfer semi-hydrogenation of terminal alkynes with a well-defined iron complex

Dalton Transactions, Journal Year: 2024, Volume and Issue: 53(8), P. 3484 - 3489

Published: Jan. 1, 2024

A bench stable iron( ii ) complex with the pincer ligand backbone was synthesized and characterized. The well-defined iron successfully utilized for dehydrogenation of DMAB subsequent transfer semi-hydrogenation terminal alkynes.

Language: Английский

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