Towards quantifying catalytic activity of homogeneous Brønsted acid catalysts

Molecular Catalysis, Journal Year: 2025, Volume and Issue: 573, P. 114846 - 114846

Published: Jan. 20, 2025

Language: Английский

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Catalytic Asymmetric Dearomatization of 2,3-Disubstituted Indoles by a [4 + 2] Cycloaddition Reaction with In Situ Generated Vinylidene ortho-Quinone Methides: Access to Polycyclic Fused Indolines

Organic Letters, Journal Year: 2024, Volume and Issue: 26(24), P. 5057 - 5062

Published: March 15, 2024

A protocol of enantioselective dearomatization 2,3-disubstituted indoles by an organocatalytic intermolecular (4 + 2) cycloaddition reaction with in situ generated vinylidene ortho-quinone methide has been documented. wide range polycyclic 2,3-fused indolines containing vicinal quaternary carbon stereocenters was readily prepared high yields and excellent diastereo- enantioselectivities.

Language: Английский

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Accessing unnatural α-amino acids with tetrasubstituted stereogenic centersviacatalytic enantioselective reactions of ketimine-type α-iminoesters/α-iminoamides

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(54), P. 8343 - 8374

Published: Jan. 1, 2023

Catalytic enantioselective synthesis methodologies have been actively explored and developed owing to the significance of chiral molecules their utilities. In particular, unnatural α-amino acids with tetrasubstituted stereogenic carbon centers (α-tertiary amino acids; ATAAs) are undoubtedly among most valuable compounds. Asymmetric addition an α-iminoester or α-iminoamide is widely recognized as a straightforward, powerful, atom-economical strategy for accessing optically active derivatives. However, this type chemistry, which relies on ketimine-type electrophiles, was quite limited only few decades ago low reactivities difficulties associated enantiofacial control. This feature article comprehensively overviews research field highlights significant progress that has made. it focuses catalyst system transition state key parameters such reactions.

Language: Английский

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Recent Advances in Asymmetric Catalysis Using p‐Block Elements

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(9)

Published: Dec. 1, 2023

The development of new methods for enantioselective reactions that generate stereogenic centres within molecules are a cornerstone organic synthesis. Typically, metal catalysts bearing chiral ligands as well organocatalysts have been employed the synthesis compounds. In this review, we highlight recent advances in main group catalysis using p-block elements (boron, aluminium, phosphorus, bismuth) complementary and sustainable approach to molecules. Several these benefit terms high abundance, low toxicity, selectivity, excellent reactivity. This minireview summarises utilisation element asymmetric value-added

Language: Английский

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Recent Developments for the Catalytic Asymmetric Synthesis of Indolin-3-one Derivatives

Organic & Biomolecular Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

2,2-Disubstituted indolin-3-ones, which are essential components in many manufactured chemicals, dyes, and naturally occurring bioactive alkaloids, have emerged as exciting synthetic targets. Much attention has been paid to accessing these units, particularly an asymmetric fashion, during the last decade. In this review article, we discuss current state of available methods with existing mechanistic pathways for chiral indolin-3-one derivatives under various catalytic systems. This overall presentation protocols access 2,2-disubstituted or fused indolin-3-ones aza-quaternary centre is categorized based on reaction modes 2-substituted-3H-indole-3-one other similar protocols.

Language: Английский

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Chiral Phosphoric Acid-Catalyzed Hydrolytic Parallel Kinetic Resolution of Racemic Epoxides and Activated Alcohols

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 18, 2025

We report a chiral phosphoric acid-catalyzed hydrolytic parallel kinetic resolution (HPKR) of racemic epoxides and activated alcohols. Using an acyloxy-assisted activation strategy, this method enables the highly stereocontrolled hydrolysis under mild conditions. A wide range aryl-substituted secondary alcohols were effectively transformed, providing corresponding with combined yields up to 99% enantiomeric ratios exceeding 99:1.

Language: Английский

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Stereoselective (3 + 3)-Cycloannulation of Carbonyl Ylides and (Z)-3-Benzylidene-3H-indoles Enabled by Cooperative Rh/Chiral Phosphoric Acid Catalysis

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 19, 2025

A diastereo- and enantioselective (3 + 3)-cycloannulation of in situ generated carbonyl ylides (Z)-3-benzylidene-3H-indoles enabled by cooperative Rh/chiral phosphoric acid catalysis is reported. This study the first to describe an synthesis cyclohepta[b]indole with oxa-bridged motif. The scope reaction broad, products were obtained moderate good yields excellent diastereoselectivities high enantioselectivities.

Language: Английский

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Molybdenum‐Catalyzed Asymmetric Amination of α‐Hydroxy Esters: Synthesis of α‐Amino Acids

Advanced Science, Journal Year: 2025, Volume and Issue: unknown

Published: March 10, 2025

Abstract Unnatural α‐amino acids are found in a wide variety of bioactive compounds ranging from proteins to pharmaceutical agents materials science. As result, the investigation efficient and simple methods for their synthesis is major purpose reaction development. In this study, it that catalyst based on molybdenum, an earth‐abundant transition metal, can facilitate amination readily accessible α‐hydroxy esters afford N ‐protected unnatural acid high yield. This process also enables enantioselective amination, which proceeds through cooperative catalysis chiral molybdenum complex with phosphoric (CPA), complements earlier procedures catalytic important class compounds. The obtained protected ester products directly useful or further utilized commercially available drugs analogs.

Language: Английский

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Controlling Stereoselectivity with Noncovalent Interactions in Chiral Phosphoric Acid Organocatalysis

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

Chiral phosphoric acids (CPAs) have emerged as highly effective Brønsted acid catalysts in an expanding range of asymmetric transformations, often through novel multifunctional substrate activation modes. Versatile and broadly appealing, these benefit from modular tunable structures, compatibility with additives. Given the unique types noncovalent interactions (NCIs) that can be established between CPAs various reactants─such hydrogen bonding, aromatic interactions, van der Waals forces─it is unsurprising catalyst systems become a promising approach for accessing diverse chiral product outcomes. This review aims to provide in-depth exploration mechanisms by which impart stereoselectivity, positioning NCIs central feature connects broad spectrum catalytic reactions. Spanning literature 2004 2024, it covers nucleophilic additions, radical atroposelective bond formations, highlighting applicability CPA organocatalysis. Special emphasis placed on structural mechanistic features govern CPA-substrate well tools techniques developed enhance our understanding their behavior. In addition emphasizing details stereocontrolling elements individual reactions, we carefully structured this natural progression specifics broader, class-level perspective. Overall, findings underscore critical role catalysis significant contributions advancing synthesis.

Language: Английский

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Aporphinol-Derived Chiral Phosphoric Acids: Synthesis and Catalytic Performance

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: April 18, 2025

A novel series of chiral phosphoric acid (CPA) catalysts based on a bioinspired aporphinol scaffold has been developed. The efficacy these CPAs is demonstrated through enantioselective transfer hydrogenation C2-substituted quinolines, achieving excellent enantioselectivities (93-99% enantiomeric excess). They also exhibit catalytic efficiency comparable to that classic acids in the asymmetric Friedel-Crafts reaction and reduction ketone. This work highlights potential aporphinol-based for diverse transformations.

Language: Английский

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