Differentiating enantiomers by directional rotation of ions in a mass spectrometer

Science, Journal Year: 2024, Volume and Issue: 383(6683), P. 612 - 618

Published: Feb. 8, 2024

Conventional mass spectrometry does not distinguish between enantiomers, or mirror-image isomers. Here we report a technique to break the chiral symmetry and differentiate enantiomers by inducing directional rotation of gas-phase ions. Dual alternating current excitations were applied manipulate motions trapped ions, including around center macro movement trap. Differences in collision cross section induced, which could be measured ion cloud profiling at high resolutions above 10,000. High-field mobility tandem analyses combined implemented using miniature trap spectrometer. The effectiveness developed method was demonstrated with variety organic compounds amino acids, sugars, several drug molecules, as well proof-of-principle ligand optimization study for asymmetric hydrogenation.

Language: Английский

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A Tailored Versatile and Efficient NHC‐Based NNC‐Pincer Manganese Catalyst for Hydrogenation of Polar Unsaturated Compounds

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(23)

Published: April 7, 2023

The reactivity of metal-hydride complexes can be harnessed by the modification ancillary ligands. With aim improving hydride-donor ability key Mn-H intermediate and reducing steric hindrance, we herein report rational design a versatile efficient NHC-based NNC-pincer Mn catalyst for hydrogenation reactions. This newly developed exhibited higher activity than corresponding NNP-pincer owing to its reduced hindrance enhanced σ-bonding orbital energy level through π-antibonding interaction. Using this highly active catalyst, rich array polar unsaturated compounds (>80 examples) including esters, N-heteroarenes, amides, carbonates, urea derivatives, were successfully hydrogenated under relatively mild conditions. work represents rare example general phosphine-free Mn-catalyzed system.

Language: Английский

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Organometallic Mn(I) Complexes in Asymmetric Catalytic (Transfer) Hydrogenation and Related Transformations

ChemCatChem, Journal Year: 2024, Volume and Issue: 16(14)

Published: March 7, 2024

Abstract Direct asymmetric hydrogenation (AH) and transfer (ATH) are among the most efficient approaches to produce chiral building blocks. Recently, these types of transformations have witnessed a shift towards use molecular catalysts based on earth‐abundant transition metals due their ready availability, economic advantage, novel properties. With particular regard manganese, catalyst development has seen both efficiency substrate scope in AH ATH greatly improved, with emergence large number well‐defined Mn‐complexes employed this field. The reaction includes C=O bonds, reduction C=N bonds reductive C=C bonds. Herein, our survey area focuses catalytic activity such complexes, versatility routes convert substrates target molecules. We consider collected findings article will be helpful reader by providing an insight into ligand design, thereby aiding future development. Moreover, review is aimed at highlighting remarkable progress made last seven years manganese complexes for enantioselective reduction.

Language: Английский

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Nickel‐Catalyzed Asymmetric Hydrogenation of α‐Substituted Vinylphosphonates and Diarylvinylphosphine Oxides

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(6)

Published: Dec. 12, 2022

Chiral α-substituted ethylphosphonate and ethylphosphine oxide compounds are widely used in drugs, pesticides, ligands. However, their catalytic asymmetric synthesis is still rare. Of the only hydrogenation methods available at present, all cases use rare metal catalysts. Herein, we report an efficient earth-abundant transition-metal nickel catalyzed affording corresponding chiral products with up to 99 % yield, 96 ee (enantiomeric excess) (99 ee, after recrystallization) 1000 S/C (substrate/catalyst); this also first study on of terminal olefins using a catalyst under hydrogen atmosphere. The mechanism was investigated via deuterium-labelling experiments calculations which indicate that two added atoms come from gas. Additionally, it believed reaction involves NiII rather than Ni0 cyclic process based weak attractive interactions between Ni olefin substrate.

Language: Английский

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Recent Advances in Nonprecious Metal Catalysis

Organic Process Research & Development, Journal Year: 2023, Volume and Issue: 27(3), P. 423 - 447

Published: Feb. 17, 2023

Nonprecious-metal-catalyzed alternatives to powerful precious metal transformations are of increasing interest in academia and the pharmaceutical industry due lower cost, better sustainability, toxicity. With continual growth broad field nonprecious catalysis (NPMC), we have chosen highlight selected articles published from March June 2022 which intended examples NPMC that feel may be especially relevant development. We aim inspire academic industrial innovation through discussion herein.

Language: Английский

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Copper‐Catalyzed Chemoselective Asymmetric Hydrogenation of C=O Bonds of Exocyclic α,β‐Unsaturated Pentanones

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(35)

Published: June 12, 2023

A highly chemoselective earth-abundant transition metal copper catalyzed asymmetric hydrogenation of C=O bonds exocyclic α,β-unsaturated pentanones was realized using H2 . The desired products were obtained with up to 99 % yield and 96 ee (enantiomeric excess) (99 ee, after recrystallization). corresponding chiral allylic pentanol can be converted into several bioactive molecules. mechanism investigated via deuterium-labelling experiments control experiments, which indicate that the keto-enol isomerization rate substrate is faster than also show Cu-H complex only catalyze chemoselectively reduction carbonyl group. Computational results multiple attractive dispersion interactions (MADI effect) between catalyst bulky substituents play important roles stabilize states reduce generation by-products.

Language: Английский

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Rhodium‐Catalyzed Asymmetric Hydrogenation and Transfer Hydrogenation of 1,3‐Dipolar Nitrones

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(14)

Published: Feb. 17, 2024

Abstract Owing to their distinctive 1,3‐dipolar structure, the catalytic asymmetric hydrogenation of nitrones hydroxylamines has been a formidable and longstanding challenge, characterized by intricate enantiocontrol susceptibility N−O bond cleavage. In this study, transfer were accomplished with tethered TsDPEN‐derived cyclopentadienyl rhodium(III) catalyst (TsDPEN: p ‐toluenesulfonyl‐1,2‐diphenylethylene‐1,2‐diamine), reaction proceeds via novel 7‐membered cyclic transition state, producing chiral up 99 % yield >99 ee. The practical viability methodology was underscored gram‐scale reactions subsequent transformations. Furthermore, mechanistic investigations DFT calculations also conducted elucidate origin enantioselectivity.

Language: Английский

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Rhodium-Catalyzed Homogeneous Asymmetric Hydrogenation of Naphthol Derivatives

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Due to their strong aromaticity and difficulties in chemo-, regio-, enantioselectivity control, asymmetric hydrogenation of naphthol derivatives 1,2,3,4-tetrahydronaphthols has remained a long-standing challenge. Herein, we report the first example homogeneous catalyzed by tethered rhodium-diamine catalysts, affording wide array optically pure high yields with excellent enantioselectivities (up 98% yield >99% ee). Mechanistic studies experimental computational approaches reveal that fluorinated solvent 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) plays vital roles control reactivity selectivity, 1-naphthol is reduced via cascade reaction pathway, including dearomative tautomerization, 1,4-hydride addition, 1,2-hydride addition sequence. A novel synergistic activation mode was proposed which HFIP assists both hydrogen molecule presence base, situ-generated fleeting keto tautomer immediately trapped Rh(III)-H species before it escapes from cage. This protocol provides straightforward practical pathway for synthesis key intermediates several chiral drugs. Particularly, Nadolol, drug treatment hypertension, angina pectoris, congestive heart failure, certain arrhythmias, enantioselectively synthesized time.

Language: Английский

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Rational Design of a Facially CoordinatingP,N,NLigand for Manganese‐Catalysed Enantioselective Hydrogenation of Cyclic Ketones

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(3)

Published: Nov. 7, 2022

DFT calculations on the full catalytic cycle for manganese catalysed enantioselective hydrogenation of a selection ketones have been carried out at PBE0-D3

Language: Английский

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Efficient Hydrogenation of N‐Heterocycles Catalyzed by NNP–Manganese(I) Pincer Complexes at Ambient Temperature

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 29(2)

Published: Oct. 4, 2022

Manganese-catalyzed hydrogenation reactions have aroused widespread interest in recent years. Among the catalytic systems described, especially PNP- and NNP-Mn pincer catalysts been reported for of aldehydes, ketones, nitriles, aldimines esters. Furthermore, compounds are efficient hydrogenolysis less reactive amides, ureas, carbonates, carbamates. Herein, synthesis application specific imidazolylaminophosphine ligands corresponding Mn complexes described. These new characterized studied by a combination experimental theoretical investigations, their activities tested several with good to excellent performance. Especially, reduction N-heterocycles can be performed under very mild conditions.

Language: Английский

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