Chiral Quaternary Ammonium Salt‐Catalyzed Enantioselective Addition Reactions of Hydantoins DOI Creative Commons

Katharina Röser,

Lucas Prameshuber,

Sajid Jahangir

et al.

Helvetica Chimica Acta, Journal Year: 2023, Volume and Issue: 107(3)

Published: Dec. 29, 2023

Abstract We herein report a protocol for the asymmetric 1,4‐addition of hydantoins to various Michael acceptors by utilizing Cinchona alkaloid‐based chiral quaternary ammonium salt catalysts. Various products were obtained with moderate good enantioselectivities and accompanying computational investigations helped identify key interactions responsible observed selectivity. DFT calculations along non‐covalent interaction plots reveal presence numerous stabilizing non‐classical hydrogen bonding other between hydantoin molecule in C−C bond forming transition states leading formation products. In addition, first proof‐of‐concept an analogous a‐sulfanylation reaction, albeit poor selectivity, is reported as well.

Language: Английский

Asymmetric phase-transfer catalysis DOI
Hyo‐Jun Lee, Keiji Maruoka

Nature Reviews Chemistry, Journal Year: 2024, Volume and Issue: 8(11), P. 851 - 869

Published: Oct. 9, 2024

Language: Английский

Citations

10
Highly Nucleophilic Pyridinamide Anions in Apolar Organic Solvents due to Asymmetric Ion Pair Association DOI Creative Commons

Veronika Burger,

Maximilian Franta,

Armin R. Ofial

et al.

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

Published: Jan. 24, 2025

Free ions in organic solvents of low polarity would be valuable tools for the activation low-reactivity substrates. However, formation unreactive ion pairs at concentrations relevant synthesis has prevented success this concept so far. On example highly nucleophilic pyridinamide phosphonium salts dichloromethane, we show that asymmetric aggregation offers a solution to general problem. A combination conductivity, diffusion-ordered NMR (DOSY), and kinetic measurements utilizing refined ionic strength-controlled benzhydrylium methodology enables unique insight into aggregation/association state nucleophilicity involved anions. This approach reveals tetraphenylphosphonium aggregate dichloromethane asymmetrically form sandwich-type cations anions together with their free counterions. The exceeds neutral reference nucleophile 9-azajulolidine (TCAP) by up 2 orders magnitude. Based on these results, suggest might pathway boost reactivity anionic nucleophiles.

Language: Английский

Citations

1
Isothiourea‐Catalyzed Enantioselective Functionalisation of Glycine Schiff Base Aryl Esters via 1,6‐ and 1,4‐Additions DOI Creative Commons
Lotte Stockhammer, Rebecca L. Craik, Uwe Monkowius

et al.

ChemistryEurope, Journal Year: 2023, Volume and Issue: 1(1)

Published: May 3, 2023

Abstract The enantioselective α‐functionalisation of glycine Schiff base aryl esters through isothiourea catalysis is successfully demonstrated for 1,6‐additions to para‐quinone methides (21 examples, up 95 : 5 dr and 96 4 er) 1,4‐ additions methylene substituted dicarbonyl or disulfonyl Michael acceptors (17 98 2 er). This nucleophilic organocatalysis approach gives access a range α‐functionalised α‐amino acid derivatives further transformations the activated ester group provide straightforward entry advanced amino acid‐based esters, amides thioesters.

Language: Английский

Citations

11
Recent advances in organocatalytic enantioselective syntheses of β-fluoroamine compounds DOI
Taeyang Do, Geun Ho Kim, Ramón Rios

et al.

Molecular Catalysis, Journal Year: 2025, Volume and Issue: 576, P. 114944 - 114944

Published: Feb. 26, 2025

Language: Английский

Citations

0
Recent Advances in Catalytic Approaches for Pyrano[2,3‐c]Pyrazole Synthesis: Green and Sustainable Perspectives DOI

Pavitra Ratanpara,

Rizwan Chavda,

Parin H. Kanaiya

et al.

ChemistrySelect, Journal Year: 2025, Volume and Issue: 10(12)

Published: March 1, 2025

Abstract This review provides a detailed look at the methods used to create pyrano[2,3‐c]pyrazole derivatives over past ten years, with focus on various catalytic techniques. The highlights progress in green chemistry, showing how catalysts such as homogeneous, heterogeneous, and nanoparticle types have been used. It also discusses new approaches like microwave‐assisted catalyst‐free synthesis. evaluates effectiveness of different based reaction efficiency, yield, sustainability. Furthermore, it explores eco‐friendly options bio‐catalysts ionic liquid catalysts, which offer scalable environmentally‐friendly for producing these important compounds. Pyrano[2,3‐c]pyrazoles were chosen their significant potential pharmaceuticals industry. emphasizes sustainable are becoming more modern particularly due reusability lower environmental impact, making them ideal industrial applications.

Language: Английский

Citations

0
Towards an asymmetric β-selective addition of azlactones to allenoates DOI Creative Commons
Behzad Nasiri,

Ghaffar Pasdar,

Paul Zebrowski

et al.

Beilstein Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 20, P. 1504 - 1509

Published: July 4, 2024

We herein report the asymmetric organocatalytic addition of azlactones to allenoates. Upon using chiral quaternary ammonium salt catalysts, i.e., Maruoka’s binaphthyl-based spirocyclic salts, various allenoates proceeds in a β-selective manner with moderate levels enantioselectivities (up 83:17 er). Furthermore, obtained products can be successfully engaged nucleophilic ring opening reactions, thus giving highly functionalized α-amino acid derivatives.

Language: Английский

Citations

2
Chiral Quaternary Ammonium Salt‐Catalyzed Enantioselective Addition Reactions of Hydantoins DOI Creative Commons

Katharina Röser,

Lucas Prameshuber,

Sajid Jahangir

et al.

Helvetica Chimica Acta, Journal Year: 2023, Volume and Issue: 107(3)

Published: Dec. 29, 2023

Abstract We herein report a protocol for the asymmetric 1,4‐addition of hydantoins to various Michael acceptors by utilizing Cinchona alkaloid‐based chiral quaternary ammonium salt catalysts. Various products were obtained with moderate good enantioselectivities and accompanying computational investigations helped identify key interactions responsible observed selectivity. DFT calculations along non‐covalent interaction plots reveal presence numerous stabilizing non‐classical hydrogen bonding other between hydantoin molecule in C−C bond forming transition states leading formation products. In addition, first proof‐of‐concept an analogous a‐sulfanylation reaction, albeit poor selectivity, is reported as well.

Language: Английский

Citations

4