Manganese‐Catalyzed Hydrosilylation Reactions

Chemistry - An Asian Journal, Journal Year: 2018, Volume and Issue: 13(17), P. 2307 - 2315

Published: May 21, 2018

Abstract Over the past few decades, manganese‐catalyzed hydrosilylation of C=O or C=C/C≡C unsaturated bonds have undergone enormous developments. In this focus review, reactions alkenes, alkynes, and carbonyl‐containing substrates catalyzed by manganese complexes are summarized. Moreover, mechanisms briefly discussed.

Language: Английский

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Manganese‐Catalyzed Direct Olefination of Methyl‐Substituted Heteroarenes with Primary Alcohols

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(29), P. 9126 - 9130

Published: May 28, 2018

Abstract Herein, we present the first catalytic direct olefination of methyl‐substituted heteroarenes with primary alcohols through an acceptorless dehydrogenative coupling. The reaction is catalyzed by a complex earth‐abundant transition metal manganese that stabilized bench‐stable NNN pincer ligand derived from 2‐hydrazinylpyridine. environmentally benign, producing only hydrogen and water as byproducts. A large number E ‐disubstituted olefins were selectively obtained high efficiency.

Language: Английский

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Manganese Catalyzed Acceptorless Dehydrogenative Coupling Reactions

ChemCatChem, Journal Year: 2019, Volume and Issue: 12(7), P. 1891 - 1902

Published: Dec. 21, 2019

Abstract Acceptorless dehydrogenative coupling (ADC) has emerged as a powerful tool in the chemists’ arsenal for construction of various carbon‐carbon and carbon‐heteroatom bonds. These protocols are highly atom economical environmentally benign they do not require pre‐functionalized starting material produce only dihydrogen (and water) by‐product. This technique, coupled with Earths’ abundant less toxic manganese catalysis, can prove to be vital strategy generation molecular complexity from simple materials. Manganese catalyzed DHC been growing interest, low‐ high‐valent catalysts have developed. were demonstrated show excellent catalytic activity formation carbon‐carbon, bonds, cascade reactions. In this mini‐review, we would like highlight recent progress that made ADC

Language: Английский

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Chromium‐Catalyzed Alkylation of Amines by Alcohols

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(29), P. 11789 - 11793

Published: March 18, 2020

Abstract The alkylation of amines by alcohols is a broadly applicable, sustainable, and selective method for the synthesis alkyl amines, which are important bulk fine chemicals, pharmaceuticals, agrochemicals. We show that Cr complexes can catalyze this C−N bond formation reaction. synthesized isolated 35 examples alkylated including 13 previously undisclosed products, use amino as alkylating agents was demonstrated. catalyst tolerates numerous functional groups, hydrogenation‐sensitive examples. Compared to many other alcohol‐based amine methods, where stoichiometric amount base required, our Cr‐based system gives yields higher than 90 % various with catalytic base. Our study indicates borrowing hydrogen or autotransfer reactions could thus be an alternative Fe, Co, Mn, noble metals in (de)hydrogenation catalysis.

Language: Английский

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Manganese‐Catalyzed anti‐Selective Asymmetric Hydrogenation of α‐Substituted β‐Ketoamides

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(36), P. 15565 - 15569

Published: May 25, 2020

Abstract A Mn‐catalyzed diastereo‐ and enantioselective hydrogenation of α‐substituted β‐ketoamides has been realized for the first time under dynamic kinetic resolution conditions. anti ‐α‐Substituted β‐hydroxy amides, which are useful building blocks synthesis bioactive molecules chiral drugs, were prepared in high yields with excellent selectivity (up to >99 % dr ee ) unprecedentedly activity (TON up 10000). The origin stereoselectivity was clarified by DFT calculations.

Language: Английский

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C‐Alkylation of Secondary Alcohols by Primary Alcohols through Manganese‐Catalyzed Double Hydrogen Autotransfer

ChemSusChem, Journal Year: 2018, Volume and Issue: 12(13), P. 3099 - 3102

Published: Sept. 21, 2018

Abstract A new Mn‐catalyzed alkylation of secondary alcohols with non‐activated is presented. The use a stable and well‐defined manganese pincer complex, stabilized by PNN ligand, together catalytic amount base enabled the conversion renewable alcohol feedstocks to broad range higher‐value in good yields water as sole byproduct. strategy eliminates need for exogenous detrimental alkyl halides well noble metal catalysts, making C‐alkylation through double hydrogen autotransfer highly sustainable environmentally benign process. Mechanistic investigations support mechanism which non‐innocent ligand plays crucial role.

Language: Английский

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Enantioselective Hydrogenation of Tetrasubstituted α,β‐Unsaturated Carboxylic Acids Enabled by Cobalt(II) Catalysis: Scope and Mechanistic Insights

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(20), P. 11384 - 11390

Published: Feb. 19, 2021

Abstract Chiral carboxylic acids are important compounds because of their prevalence in pharmaceuticals, natural products and agrochemicals. Asymmetric hydrogenation α,β‐unsaturated has been widely recognized as one the most efficient synthetic approaches to afford such compounds. Although related asymmetric di‐ trisubstituted unsaturated with noble metals is well established, challenging tetrasubstituted rarely reported. We demonstrate enantioselective cyclic acyclic via cobalt(II) catalysis. This protocol showed broad substrate scope gave chiral good yields excellent enantiocontrol (up 98 % yield 99 ee ). Combined experimental computational mechanistic studies support a Co II catalytic cycle involving migratory insertion σ‐bond metathesis processes. DFT calculations reveal that enantioselectivity may originate from steric effect between phenyl groups ligand substrate.

Language: Английский

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Manganese‐Catalyzed Dual‐Deoxygenative Coupling of Primary Alcohols with 2‐Arylethanols

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(46), P. 15143 - 15147

Published: Oct. 26, 2018

Abstract Reported herein is a general and efficient dual‐deoxygenative coupling of primary alcohols with 2‐arylethanols catalyzed by well‐defined Mn/PNP pincer complex. This reaction the first example catalytic dual‐deoxygenation using non‐noble‐metal catalyst. Both deoxygenative homocoupling (17 examples) their cross‐coupling other (20 proceeded smoothly to form corresponding alkenes dehydrogenation deformylation sequence.

Language: Английский

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α‐Alkylation of Ketones with Secondary Alcohols Catalyzed by Well‐Defined Cp*Co^III‐Complexes

ChemSusChem, Journal Year: 2019, Volume and Issue: 12(15), P. 3463 - 3467

Published: June 26, 2019

Although α-alkylation of ketones with primary alcohols by transition-metal catalysis is well-known, the same process secondary arduous and complicated self-condensation. Herein a well-defined, high-valence cobalt(III)-catalyst was applied for successful alcohols. A wide-variety alcohols, which include cyclic, acyclic, symmetrical, unsymmetrical compounds, employed as alkylating agents to produce β-alkyl aryl ketones.

Language: Английский

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Light Runs Across Iron Catalysts in Organic Transformations

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 26(66), P. 15052 - 15064

Published: July 2, 2020

Over the past decades, organometallic complexes with precious elements, such as ruthenium and iridium, are widely used visible-light photoredox catalysts. Recently, more based on earth-abundant inexpensive elements have been sensitizers in photochemistry. Although photoexcited state lifetimes of iron typically shorter than those traditional photosensitizers, utilization catalysts photochemistry has sprung up owing to their abundance, low price, nontoxicity, novel properties, including exhibiting ligand metal charge transfer states. This concept focuses recent advances light-driven catalysis organic transformations, iron/photoredox dual catalysis, light-induced generation active The prospect for future this field is also discussed.

Language: Английский

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