Advances in chitosan-based drug delivery systems: A comprehensive review for therapeutic applications

European Polymer Journal, Journal Year: 2024, Volume and Issue: 210, P. 112983 - 112983

Published: March 26, 2024

Language: Английский

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Enantioselective Aminative Dearomatization of Indoles via Electrophilic 1,6-Addition of p-Quinone Diimides (p-QDIs)

Organic Letters, Journal Year: 2024, Volume and Issue: 26(23), P. 4932 - 4937

Published: June 3, 2024

Herein we report the first use of p-quinone diimide for aminative dearomatization 2,3-disubstituted indoles to furnish C3 aza-quaternary chiral indolenines. This approach, which proceeds via an electrophilic 1,6-addition diimide, allows synthesis array optically active indolenines with high yields and excellent enantioselectivities. A one-pot approach same has also been established further improve synthetic accessibility this protocol.

Language: Английский

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Mechanism and Origins of Regio- and Stereoselectivities of NHC-Catalyzed Dearomative Annulation of Benzoazoles and Cinnamaldehydes from DFT

The Journal of Physical Chemistry A, Journal Year: 2025, Volume and Issue: unknown

Published: March 5, 2025

A theoretical study on the mechanism, regioselectivity, and enantioselectivity of NHC-catalyzed dearomatizing annulation benzoxazoles with enals has been conducted using density functional theory calculations. Our calculated results indicate that favored mechanism occurs through eight reaction steps: initial binding NHC to enals, followed by formation Breslow intermediate via proton transfer. Subsequent oxidation generates α,β-unsaturated acylazolium intermediate, which can undergo Michael addition benzoxazoles. Sequential protonation/deprotonation/cyclization produces six-membered cyclic undergoes catalyst elimination, leading final product. DABCO·H+ was found play important roles in transfer cyclization. Without DABCO·H+, energy barrier up 44.2 kcal/mol for step 2 is too high be accessible. With corresponding value lowered 18.6 kcal/mol. The cyclization 7.4 DABCO·H+. determines both regioselectivity. According NCI analysis, controlled strong interactions (such as C-H···O, C-H···N, π···π) between We also discuss solvent substituent effects role NHC. mechanistic insights obtained present would help improving current systems or designing new synthetic routes.

Language: Английский

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Progress in the Asymmetric Dearomatization Reactions of Arenols

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 9503 - 9543

Published: May 20, 2025

Language: Английский

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Dearomative spiroannulation of indoles enabled by the diaza-[1,2]-Wittig rearrangement

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(6), P. 1685 - 1691

Published: Jan. 1, 2024

Reported herein is the first diaza-[1,2]-Wittig rearrangement-enabled dearomative spiroannulation reaction of indoles. This protocol features metal-free conditions, a redox-neutral process, broad substrate scope, and good yield.

Language: Английский

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Copper-catalyzed asymmetric dearomatizing amination of 2-naphthols: Csp2–N coupling via 1,3-reductive elimination

Science China Chemistry, Journal Year: 2024, Volume and Issue: 67(8), P. 2694 - 2700

Published: July 2, 2024

Language: Английский

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Enantioselective Dearomatization of Substituted Phenols via Organocatalyzed Electrophilic Amination

Organic Letters, Journal Year: 2023, Volume and Issue: 25(31), P. 5838 - 5843

Published: July 31, 2023

Highly efficient and stereoselective dearomatization of substituted phenols was achieved via chiral phosphoric acid-catalyzed electrophilic para-amination with commercially available azodicarboxylates. This protocol readily afforded a series 2,5-cyclohexadienones bearing 4-aza-quaternary stereocenters excellent yields enantioselectivities (≤99% yield >99% ee). Easy scale-up this reaction to gram scale diverse derivatizations the products into α-tertiary amines heterocycles derivatives well demonstrated potential method.

Language: Английский

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Mechanisms, regio- and stereoselectivities involved in NHC catalyzed dearomatizing annulation of ester with ylide: A computational study

Molecular Catalysis, Journal Year: 2024, Volume and Issue: 560, P. 114146 - 114146

Published: April 16, 2024

Language: Английский

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Pyrroloindoles as Therapeutically Invaluable Agents: A Review on their Diverse Synthetic Methodologies

Asian Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 13(2)

Published: Dec. 23, 2023

Abstract In the realm of medicinal chemistry, heterocyclic compounds play a vital role due to their diverse pharmacological properties, especially, pyrroloindoles standing out as crucial motifs in drug development. Pyrroloindoles, which are formed by combining indole and pyrrole rings, exhibit unique characteristics serve integral components numerous drugs natural compounds. The synthesis is challenging complex ring structures substitution patterns. This comprehensive review compiles various synthetic strategies for obtaining pyrroloindole derivatives via metal‐catalyzed reactions; cyclopropanation/ opening/ iminium cyclization (CRI reaction); organocatalytic cascade addition‐cyclization; 1,3‐dipolar cycloaddition; Brønsted acid‐catalyzed [3+2] cyclodimerization; closure mechanisms; thermally‐induced ring‐opening condensation visible‐light photocatalytic asymmetric reactions providing valuable resource organic chemists researchers interested derivatives. These pivotal discovery thus, making this an indispensable reference.

Language: Английский

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Formal Dearomative Hydroamination of 2-Arylphenols

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

Published: Dec. 20, 2024

An acid-promoted dearomative rearrangement of

Language: Английский

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