Lutidine‐Based Chiral Pincer Manganese Catalysts for Enantioselective Hydrogenation of Ketones

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(15), P. 4973 - 4977

Published: Feb. 18, 2019

A series of MnI complexes containing lutidine-based chiral pincer ligands with modular and tunable structures has been developed. The complex shows unprecedentedly high activities (up to 9800 TON; TON=turnover number), broad substrate scope (81 examples), good functional-group tolerance, excellent enantioselectivities (85-98 % ee) in the hydrogenation various ketones. These aspects are rare earth-abundant metal catalyzed hydrogenations. utility protocol have demonstrated asymmetric synthesis a variety key intermediates for drugs. Preliminary mechanistic investigations indicate that an outer-sphere mode substrate-catalyst interactions probably dominates catalysis.

Language: Английский

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Cobalt–Pincer Complexes in Catalysis

Chemistry - A European Journal, Journal Year: 2018, Volume and Issue: 25(1), P. 122 - 143

Published: Sept. 5, 2018

Abstract Non‐noble metal catalysts based on pincer type compounds are of special interest for organometallic chemistry and organic synthesis. Next to iron manganese, currently cobalt–pincer complexes successfully applied in various catalytic reactions. In this review the recent progress (de)hydrogenation, transfer hydrogenation, hydroboration hydrosilylation as well dehydrogenative coupling reactions using is summarised.

Language: Английский

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Hydrogenation of CO₂‐Derived Carbonates and Polycarbonates to Methanol and Diols by Metal–Ligand Cooperative Manganese Catalysis

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(41), P. 13439 - 13443

Published: Aug. 13, 2018

The first base-metal-catalysed hydrogenation of CO2 -derived carbonates to alcohols is presented. reaction proceeds under mild conditions in the presence a well-defined manganese complex with loading as low 0.25 mol %. non-precious-metal homogenous catalytic system provides an indirect route for conversion into methanol co-production value-added (vicinal) diols yields up 99 Experimental and computational studies indicate metal-ligand cooperative catalysis mechanism.

Language: Английский

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Manganese Catalyzed Hydrogenation of Organic Carbonates to Methanol and Alcohols

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(37), P. 12076 - 12080

Published: July 23, 2018

The first example of a homogeneous catalyst based on an earth-abundant metal for the hydrogenation organic carbonates to methanol and alcohols is reported. Based mechanistic investigation, which indicates metal-ligand cooperation between manganese center N-H group pincer ligand, we propose that occurs via formate aldehyde intermediates. reaction offers indirect route conversion CO2 methanol, coupled with use earth abundant catalyst, makes overall process environmentally benign sustainable.

Language: Английский

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Phosphine‐Free NNN‐Manganese Complex Catalyzed α‐Alkylation of Ketones with Primary Alcohols and Friedländer Quinoline Synthesis

Advanced Synthesis & Catalysis, Journal Year: 2018, Volume and Issue: 360(17), P. 3233 - 3238

Published: June 29, 2018

Abstract Herein, we report a very simple and inexpensive catalytic system based on Earth's abundant transition metal manganese bench‐stable phosphine‐free NNN‐pincer ligand for an atom‐efficient α‐alkylations of ketones with primary alcohols via hydrogen‐autotransfer C−C bond formation protocol. The precatalyst could be generated in situ activated by using amount base under milder conditions. A range were efficiently diversified broad good to excellent isolated yields. Remarkably, this catalyst also employed the synthesis quinoline derivatives 2‐aminobenzyl alcohol as alkylating agent. later reaction is highly benign producing only hydrogen water byproducts. magnified image

Language: Английский

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Manganese‐Catalyzed Dehydrogenative Alkylation or α‐Olefination of Alkyl‐Substituted N‐Heteroarenes with Alcohols

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(29), P. 9131 - 9135

Published: May 2, 2018

Catalysis with earth-abundant transition metals is an option to help save our rare noble-metal resources and especially interesting when novel reactivity or selectivity patterns are observed. We report here on a reaction, namely the dehydrogenative alkylation α-olefination of alkyl-substituted N-heteroarenes alcohols. Manganese complexes developed in laboratory catalyze reaction high efficiency whereas iron cobalt stabilized by same ligands essentially inactive. Hydrogen liberated during bromine iodine functional groups as well olefins tolerated. A variety can be functionalized, benzylic aliphatic alcohols undergo reaction.

Language: Английский

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Manganese‐Catalyzed Asymmetric Hydrogenation of Quinolines Enabled by π–π Interaction**

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(10), P. 5108 - 5113

Published: Nov. 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.

Language: Английский

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Catalytic Hydrogenation of Cyclic Carbonates using Manganese Complexes

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(41), P. 13449 - 13453

Published: Aug. 22, 2018

Catalytic hydrogenation of cyclic carbonates to diols and methanol was achieved using a molecular catalyst based on earth-abundant manganese. The complex [Mn(CO)

Language: Английский

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Catalytic C₁ Alkylation with Methanol and Isotope‐Labeled Methanol

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(3), P. 775 - 779

Published: Nov. 20, 2018

Abstract A metal‐catalyzed methylation process has been developed. By employing an air‐ and moisture‐stable manganese catalyst together with isotopically labeled methanol, a series of D‐, CD 3 ‐, 13 C‐labeled products were obtained in good yields under mild reaction conditions water as the only byproduct.

Language: Английский

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Manganese‐Catalyzed β‐Methylation of Alcohols by Methanol

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(4), P. 1485 - 1490

Published: Nov. 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.

Language: Английский

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