Optimizing Phosphine Ligands for Ruthenium Catalysts in Asymmetric Hydrogenation of β-Keto Esters: The Role of Water in Activity and Selectivity

Molecular Catalysis, Journal Year: 2025, Volume and Issue: 574, P. 114877 - 114877

Published: Feb. 4, 2025

Language: Английский

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Half-Sandwich Ru(II) Complexes Featuring Metal-Centered Chirality: Configurational Stabilization by Ligand Design, Preparation via Kinetic Resolution, and Application in Asymmetric Catalysis

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

Published: Feb. 12, 2025

While it is well established that half-sandwich Ru(II) complexes possess metal-centered chirality, effective strategies to leverage their chirality toward asymmetric synthesis have been challenging due the configurational lability of metal stereocenters. The typically mediated by enantiopure ligands, which occupy a relatively narrow chemical space compared achiral counterparts. We demonstrate ligands can be used access chiral-at-ruthenium with exceptionally high stability. Key success introduction rigid bidentate ligand minimized dihedral angle between pyridyl and phenolic moieties, proved for preventing racemization. Computational studies revealed energetic factors contributing exceptional stability enabled planar structure successful design. These optically active incorporating aldehyde moieties were obtained NHC-catalyzed kinetic resolution excellent selectivities (s-factor up >200, ee 99%). further they are highly chiral catalysts 1,6-conjugate addition glycine ester para-quinone methide.

Language: Английский

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Synthesis of Chiral Vicinal Amino Alcohol Derivatives via Lewis Acid‐Catalyzed Asymmetric Ring Opening of Aziridines with Alcohols and Carboxylic Acids

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(7), P. 1654 - 1660

Published: Feb. 7, 2024

Abstract Under the catalysis of a Cu(I) or Ag(I) salt with chiral diphosphine ligand, enantioselective nucleophilic ring opening racemic 2‐styrenylaziridines via kinetic resolution dynamic asymmetric transformation (DyKAT) and meso aziridines desymmetrization alcohols was realized. The reaction provided range vicinal amino ether derivatives in 47%‐98% yields 50%–98% ee. could be extended to aliphatic carboxylic acids as nucleophiles. synthetic utility demonstrated four‐step formal synthesis diastereomer antirythmetic agent vernakalant.

Language: Английский

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Iridium-Catalyzed Asymmetric Hydrogenation of Unfunctionalized Cycloalkenes to Access Chiral 2-Aryl Tetralins

Organic Letters, Journal Year: 2024, Volume and Issue: 26(27), P. 5850 - 5855

Published: July 1, 2024

The transition-metal catalyzed asymmetric hydrogenation of unfunctionalized alkenes is challenging. Herein, we report an efficient iridium-catalyzed cycloalkenes, delivering chiral 2-aryl tetralins in excellent yields and with moderate to enantioselectivities. reaction can be performed on a gram-scale low catalyst loading (S/C = 1000), the reduced product was obtained without erosion enantioselectivity. Deuterium experiments indicated that C═C bond substrate hydrogenated directly isomerization.

Language: Английский

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Enantioselective Synthesis of Chiral β²-Amino Phosphorus Derivatives via Nickel-Catalyzed Asymmetric Hydrogenation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 27, 2024

Compared with chiral β3-amino phosphorus compounds, which can be easily derived from natural optically pure α-amino acids, obtaining β2-amino derivatives remains a challenge. These derivatives, cannot amino possess unique biological activities or potential catalytic activities. Herein, highly enantioselective hydrogenation for the preparation of E-β-enamido compounds is reported by using green and low-cost earth-abundant metal nickel catalyst (13 examples 99% ee). In particular, this system provides same enantiomer product E- Z-alkene substrates, E/Z-substrate mixtures provide good results (up to 96% The products diversely derivatized, exhibit as novel β2-aminophosphine ligands. Density functional theory calculations reveal that weak attractive interactions between substrate are crucial achieving perfect enantioselectivities. addition, different coordination modes Z-substrates may result in formation product.

Language: Английский

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Iridium-Catalyzed 1,3-Rearrangement of Allylic Ethers

Organic Letters, Journal Year: 2023, Volume and Issue: 25(48), P. 8727 - 8732

Published: Nov. 29, 2023

The 1,3-rearrangement of allylic derivatives has rarely been reported, except for alcohols. Herein, we describe an iridium-catalyzed readily available ethers to access the difficultly prepared with a large steric hindrance. developed method shows broad substrate scope and could be used in late-stage modification several natural products. In addition, possible reaction pathway is also provided on basis control experiments.

Language: Английский

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Design and Synthesis of Diphosphine Ligands Based on the Chiral Biindolyl Scaffold and Their Application in Transition-Metal Catalysis

Organic Letters, Journal Year: 2024, Volume and Issue: 26(8), P. 1623 - 1628

Published: Feb. 16, 2024

An extremely concise, scalable, and stereoselective synthesis of a privileged chiral skeleton based on 2,2′-biindolyl commercially available building blocks has been developed. This novel allows for easy access to range bisphosphine ligands (decagram scale, up 58% total yield, only three steps). The synthetic method is characterized by an efficient central-to-axial chirality transfer strategy. In particular, the superior performance demonstrated in diverse reactions, including several asymmetric hydrogenations, conjugate reductions, cycloisomerization indicating great potential application newly developed backbones further modifications exploration catalysts.

Language: Английский

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Eight-membered and larger rings

Progress in heterocyclic chemistry, Journal Year: 2024, Volume and Issue: unknown, P. 497 - 517

Published: Jan. 1, 2024

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2-([1,1′-Biphenyl]-4-yl)-5-[(E)-2-(3-methoxy-1-phenyl-1H-pyrazol-4-yl)ethenyl]-3,3-dimethyl-3H-indole

Molbank, Journal Year: 2024, Volume and Issue: 2024(4), P. M1927 - M1927

Published: Nov. 28, 2024

The ligandless palladium-catalyzed Heck reaction of 4-ethenyl-3-methoxy-1-phenyl-1H-pyrazole and 2-([1,1′-biphenyl]-4-yl)-5-bromo-3,3-dimethyl-3H-indole gave the previously unreported 2-([1,1′-biphenyl]-4-yl)-5-[(E)-2-(3-methoxy-1-phenyl-1H-pyrazol-4-yl)ethenyl]-3,3-dimethyl-3H-indole in 45% yield. compound was characterized using NMR, FT-IR spectroscopy, HRMS data. optical properties were investigated tetrahydrofuran by UV-Vis fluorescence spectroscopy.

Language: Английский

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Advances in Asymmetric Hydrogenation of Unfunctionalized Enol Ethers

Asian Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 29, 2024

Abstract Asymmetric hydrogenation of enol ethers has emerged as a valuable and environmentally friendly method for the preparation optically active cyclic acyclic ethers, some which have demonstrated substantial potential application in synthesis compounds total natural products. Over past few decades, significant attention been devoted to use transition‐metal catalysts, particularly those containing chiral phosphine‐phosphine, phosphine‐amine, or carbene ligands, unfunctionalized ethers. In parallel, frustrated Lewis pair catalysts also successfully applied this transformation, enabling efficient production various This review highlights momentum most notable advances enantioselective (with only alkyl aryl substituents on vinyl group). Owing ubiquitous industrial interest, utility related derivatives is included.

Language: Английский

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