Recent Advances in the Enantioselective Synthesis of Chiral Amines via Transition Metal-Catalyzed Asymmetric Hydrogenation

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(1), P. 269 - 339

Published: Oct. 22, 2021

Chiral amines are key structural motifs present in a wide variety of natural products, drugs, and other biologically active compounds. During the past decade, significant advances have been made with respect to enantioselective synthesis chiral amines, many them based on catalytic asymmetric hydrogenation (AH). The review covers use AH bearing stereogenic center either α, β, or γ position nitrogen atom, reported from 2010 2020. Therefore, we provide an overview recent imines, enamides, enamines, allyl N-heteroaromatic

Language: Английский

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Frustrated Lewis Pairs Catalyzed Asymmetric Metal-Free Hydrogenations and Hydrosilylations

Accounts of Chemical Research, Journal Year: 2017, Volume and Issue: 51(1), P. 191 - 201

Published: Dec. 15, 2017

ConspectusThe use of frustrated Lewis pairs is an extremely important approach to metal-free hydrogenations. In contrast the rapid growth catalytic reactions, asymmetric hydrogenations are far less developed due a severe shortage readily available chiral pair catalysts with high activities and selectivities. Unlike stable base component pairs, moisture-sensitive boron acid difficult prepare. The development convenient methods for quick construction acids therefore great interest.In this Account, we summarize our recent studies on pair-catalyzed, hydrosilylations. To address highly active selective catalysts, novel strategy in situ preparation by hydroboration dienes or diynes Piers' borane without further purification, which allows act like ligands. This ensures useful toolbox hydrosilylations operationally simple. Another using combinations bases containing hydridic acidic hydrogen atoms, respectively, as type pairs. Such systems provide opportunity simple origins induction.With diene-derived broad range unsaturated compounds, such imines, silyl enol ethers, 2,3-disubstituted quinoxalines, polysubstituted quinolines, all viable substrates give corresponding products good yields enantioselectivities and/or stereoselectivities. These very effective bulky substrates, substrate scope these has been dramatically expanded.Chiral alkenylboranes were designed enhance rigidity framework modify acidity through resulting double bonds. Frustrated phosphines class Piers-type 1,2-dicarbonyl they desired enantioselectivities. Moreover, transfer imines quinoxalines ammonia source have achieved (R)-tert-butylsulfinamide catalyst. Mechanistic suggested that occurs via 8-membered ring transition state, regeneration reactive concerted 6-membered state.

Language: Английский

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Recent Advances in Homogeneous Catalysts for the Asymmetric Hydrogenation of Heteroarenes

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(23), P. 13834 - 13851

Published: Nov. 12, 2020

The asymmetric hydrogenation of heteroarenes has recently emerged as an effective strategy for the direct access to enantioenriched, saturated heterocycles. Although several homogeneous catalyst systems have been extensively developed with high levels chemo- and stereoselectivity, development mild conditions that allow efficient stereoselective a broad range substrates remains challenge. This Perspective highlights recent advances in catalysis heteroarene inspiration further catalysts, addresses underdeveloped areas limitations current technology.

Language: Английский

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Asymmetric Hydrogenation of Unprotected Indoles Catalyzed by η⁶-Arene/N-Me-sulfonyldiamine–Ru(II) Complexes

Journal of the American Chemical Society, Journal Year: 2016, Volume and Issue: 138(35), P. 11299 - 11305

Published: Aug. 10, 2016

Protecting-group-free transformation is a challenging and important issue in atom-economical organic synthesis. The η(6)-arene/N-Me-sulfonyldiamine-Ru(II)-BF4 complex-catalyzed asymmetric hydrogenation of 2-substituted unprotected indoles weakly acidic hexafluoroisopropanol gives optically active indoline compounds with up to >99% ee. Under mild reaction media, halogen atoms synthetically protecting groups (e.g., silyl ether, acetal, benzyl ester) on are maintained, which advantageous for the synthesis further complex molecules.

Language: Английский

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Highly Enantioselective Direct Synthesis of Endocyclic Vicinal Diamines through Chiral Ru(diamine)‐Catalyzed Hydrogenation of 2,2′‐Bisquinoline Derivatives

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 55(41), P. 12891 - 12894

Published: Sept. 16, 2016

Abstract An asymmetric hydrogenation of 2,2′‐bisquinoline and bisquinoxaline derivatives, catalyzed by chiral cationic ruthenium diamine complexes, was developed. A broad range endocyclic vicinal diamines were obtained in high yields with excellent diastereo‐ enantioselectivity (up to 93:7 dl / meso >99 % ee ). These could be easily transformed into a new class N‐heterocyclic carbenes (NHCs), which are important but difficult access.

Language: Английский

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Bifunctional Oxo-Tethered Ruthenium Complex Catalyzed Asymmetric Transfer Hydrogenation of Aryl N-Heteroaryl Ketones

Organic Letters, Journal Year: 2017, Volume and Issue: 19(8), P. 2094 - 2097

Published: April 3, 2017

A facile asymmetric transfer hydrogenation of ortho-substituted aryl N-heteroaryl ketones and non-ortho-substituted N-oxide using a readily available oxo-tethered ruthenium complex as catalyst sodium formate hydrogen source in an aqueous solution has been discovered. variety chiral methanols were obtained with up to 99.9% ee.

Language: Английский

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A diversity of recently reported methodology for asymmetric imine reduction

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(20), P. 3312 - 3342

Published: Jan. 1, 2020

This review describes recent developments in enantioselective imine reduction, including related substrates which a CN bond is the target for and in situ methods.

Language: Английский

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Asymmetric Hydrogenation of Quinoline Derivatives Catalyzed by Cationic Transition Metal Complexes of Chiral Diamine Ligands: Scope, Mechanism and Catalyst Recycling

The Chemical Record, Journal Year: 2016, Volume and Issue: 16(6), P. 2697 - 2711

Published: Aug. 24, 2016

Abstract This personal account is focused on the asymmetric hydrogenation of quinolines and their analogues recently developed by using phosphorus‐free chiral cationic ruthenium(II)/ η 6 ‐arene‐ N ‐monosulfonylated diamine complexes. In our initial study, Ru‐diamine complexes were found to be highly effective catalysts for difficult quinoline substrates in room temperature ionic liquids (RTILs) with unprecedentedly excellent enantioselectivity. Our further systematic study revealed that a wide range derivatives could efficiently hydrogenated alcoholic solvents, or under solvent‐free concentrated conditions good stereoselectivity. Complexes iridium also catalyze undegassed solvent. Asymmetric tandem reduction various 2‐(aroylmethyl)quinolines was achieved high yield enantioselectivity diastereoselectivity. More challenging substrates, alkyl‐ aryl‐substituted 1,5‐ 1,8‐naphthyridine successfully these ruthenium give 1,2,3,4‐tetrahydronaphthyridines Unlike ketones, reduced via stepwise H + /H ‐ transfer process outside coordination sphere rather than concerted mechanism. The originates from CH/π attraction between ‐arene ligand Ru‐complex fused phenyl ring dihydroquinoline 10‐membered transition state participation TfO anion. addition, Ru‐catalyzed carried out some environmentally benign reaction media, such as water, RTILs oligo(ethylene glycol)s (OEGs). latter two cases, unique chemoselectivity and/or reactivity observed. Catalyst recycling realized [BMIM]PF OEGs well magnetic nanoparticles. Applications this catalytic protocol exemplified employments products syntheses important natural alkaloids, pharmaceutical intermediates, ligands. image

Language: Английский

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Transition metal-free α-methylation of 1,8-naphthyridine derivatives using DMSO as methylation reagent

Organic & Biomolecular Chemistry, Journal Year: 2019, Volume and Issue: 17(31), P. 7416 - 7424

Published: Jan. 1, 2019

A practical approach to the direct α-methylation of 1,8-naphthyridines under mild reaction conditions has been developed using simple and readily available DMSO as a convenient environmentally friendly carbon source.

Language: Английский

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Ruthenium-Catalyzed Enantioselective Hydrogenation of Phenanthridine Derivatives

Organic Letters, Journal Year: 2017, Volume and Issue: 19(6), P. 1458 - 1461

Published: March 6, 2017

The first asymmetric hydrogenation of phenanthridines catalyzed by chiral cationic ruthenium diamine complexes has been developed with up to 92% ee and full conversions. choice the counteranion catalyst was found be critical for achieving high enantioselectivity. In addition, obtained 5,6-dihydrophenanthridine could used as a hydride donor organocatalytic transfer hydrogenation.

Language: Английский

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