Recent Advances in Catalytic Asymmetric Aza‐Michael Addition Triggered Cascade Reactions

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(20), P. 4667 - 4694

Published: Aug. 28, 2021

Abstract As an important branch of the Michael addition reaction, aza‐Michael cascade reaction has been developed rapidly in recent years. This is because serves as method for effectively constructing functionalized C−N bonds, which can be widely used synthesis chiral drugs and their intermediates natural products. Given importance this topic, review highlights developments triggered reactions asymmetric synthesis, including aza‐Michael/Michael, aza‐Michael/Aldol, aza‐Michael/Henry, aza‐Michael/hemiacetal, aza‐Michael/Mannich, aza‐Michael/alkylation, aza‐Michael/cyclization, aza‐Michael/ring‐opening, aza‐Michael‐IED/HAD, aza‐Michael/INCR, aza‐Michael/1,6‐conjugate reactions. In paper, mechanism derivatization experiments different are timely introduced to provide a more comprehensive theoretical basis subsequent studies. magnified image

Language: Английский

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Dearomative Periphery Modification of Quinolinium Salts to Assemble Ring-Encumbered Pyrrolidine–Tetrahydroquinoline Polycycles

Organic Letters, Journal Year: 2022, Volume and Issue: 24(10), P. 2008 - 2013

Published: March 10, 2022

We report an unexpected dearomative periphery modification strategy for transforming quinolinium salts into structurally crowded pyrrolidine–tetrahydroquinoline polycyclic systems with complete regio- and diastereoselectivity. Importantly, the reaction pathway was regulated by simply tuning substituents, achieving substituent-directed divergent synthesis. The notable features of this transformation include readily available starting materials, green conditions, a simple workup procedure, high bond- ring-forming efficiency, diverse

Language: Английский

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Enantioselective dearomative [3+2] cycloaddition of 2-nitrobenzofurans with aldehyde-derived Morita–Baylis–Hillman carbonates

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(62), P. 9144 - 9147

Published: Jan. 1, 2019

The phosphine-catalyzed asymmetric dearomative [3+2] cycloaddition of 2-nitrobenzofurans with aldehyde-derived Morita-Baylis-Hillman (MBH) carbonates or allenoate was developed. reaction MBH resulted in a series cyclopentabenzofurans containing three contiguous stereocenters good to high yields, diastereoselectivities and enantioselectivities. use also gave the target product moderate enantioselectivity.

Language: Английский

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Enantioselective Synthesis of Fused Polycyclic Tropanes via Dearomative [3 + 2] Cycloaddition Reactions of 2-Nitrobenzofurans

Organic Letters, Journal Year: 2019, Volume and Issue: 22(1), P. 164 - 167

Published: Dec. 23, 2019

A straight synthetic approach to fused polycyclic tropane scaffold formation through an asymmetric dearomatization cycloaddition process of 2-nitrobenzofurans with cyclic azomethine ylides was successfully developed. In the presence a chiral copper complex, derived from Cu(OAc)2 and diphosphine ligand, series derivatives were obtained in high yields (75–91%) excellent enantioselectivities (90–98%). The utility this method showcased by facile transformation product.

Language: Английский

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Organocatalytic Asymmetric Dearomatization of 3-Nitroindoles and 3-Nitrobenzothiophenes via Thiol-Triggered Diastereo- and Enantioselective Double Michael Addition Reaction

Organic Letters, Journal Year: 2019, Volume and Issue: 21(14), P. 5452 - 5456

Published: June 28, 2019

Organocatalytic asymmetric dearomatization of 3-nitroindoles and 3-nitrobenzothiophenes by reaction with ethyl 4-mercapto-2-butenoate has been developed. A range chiral tetrahydrothiopheneindolines tetrahydrothiophenebenzothiophenes bearing three contiguous stereocenters are obtained in high yields good diastereoselectivities excellent enantioselectivities. This is the first example thiol-triggered catalytic 3-nitrobenzothiophenes.

Language: Английский

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Rapid and practical access to diverse quindolines by catalyst-free and regioselectivity-reversed Povarov reaction

Cell Reports Physical Science, Journal Year: 2021, Volume and Issue: 2(6), P. 100448 - 100448

Published: June 1, 2021

The Povarov reaction, a formal [4 + 2] cycloaddition between N-aryl imines and electron-rich dienophiles, has been defined as an efficient method to approach tetrahydroquinolines well established in the past decades. In general, heterosubstituted alkenes have served most popular dienophiles achieve exclusive regioselectivity. However, use of Lewis acids Brønsted catalysts is required these transformations, and, our knowledge, reaction alkynes not reported. Here, we disclose catalyst-free formyl-ynamides with anilines for rapid practical synthesis diverse range valuable quindolines, which only represents first ynamides best knowledge but also constitutes very rare example ynamide cyclization reaction. This [1 2 3] annulation shows reversed regioselectivity compared previous protocols.

Language: Английский

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Recent Dearomatization Strategies of Benzofurans and Benzothiophenes

Asian Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 10(5), P. 932 - 948

Published: March 10, 2021

Abstract This review article discusses about the recent developments in area of strategies for dearomatization benzofurans and benzothiophenes (2010–2020). The readers can understand current state art this intriguingly important organic synthesis generation diversely functionalized molecules, polycyclic systems from highly abundant benzothiophenes. We hope that would help synthetic community design development new as well further growth novel rapidly growing research.

Language: Английский

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Recent Advances in Synthetic Strategies to 2,3-Dihydrobenzofurans

Synthesis, Journal Year: 2020, Volume and Issue: 52(10), P. 1451 - 1477

Published: March 16, 2020

This review gives an overview on recent developments in methods for the construction of compounds with 2,3-dihydrobenzo­furan core period 2012 to 2019. Interest 2,3-dihydrobenzofurans is constantly increasing. The are divided into intermolecular and intramolecular approaches. Intermolecular approaches subdivided according parent intermediate key reaction, while by which bond formed reaction. transformation benzofurans dihydrobenzofurans other miscellaneous also discussed. Approaches useful synthesis natural products emphasized. 1 Introduction 2 2.1 o-Quinone Methides o-Quinones 2.2 p-Quinone p-Quinones 2.3 Nitrogen-Containing Phenols Quinones 2.4 o-Hydroxyphenylcarbonyl Derivatives 2.5 Miscellaneous 3 Intramolecular 3.1 O–C2 Bond Forming 3.2 C2–C3 3.3 C3–Aryl 3.4 O–Aryl 4 From BF DHB 5 Rearrangements Aromatizations

Language: Английский

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Catalytic asymmetric dearomative [4 + 2] annulation of 2-nitrobenzofurans and 5H-thiazol-4-ones: stereoselective construction of dihydrobenzofuran-bridged polycyclic skeletons

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(22), P. 6330 - 6336

Published: Jan. 1, 2021

An organocatalytic asymmetric dearomative [4 + 2] annulation of 2-nitrobenzofurans and 5 H -thiazol-4-ones is developed for the construction dihydrobenzofuran-bridged polycyclic skeletons with good results.

Language: Английский

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Recent advances in the transition metal-free synthesis of heterocycles from α,β-unsaturated ketones

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(19), P. 5306 - 5357

Published: Jan. 1, 2022

The review highlights the transition metal-free methodologies developed for synthesising various heterocyclic compounds by utilising α,β -unsaturated ketones as valuable synthons during period of 2009 to 2020.

Language: Английский

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