Organocatalytic Nazarov-type cyclization of 3-alkynyl-2-indolylmethanols: construction of axially chiral cyclopenta[b]indole scaffolds

Chemical Synthesis, Journal Year: 2023, Volume and Issue: 3(1), P. 6 - 6

Published: Jan. 1, 2023

In recent years, it has become an urgent task to design new types of indole-based platform molecules for Nazarov-type cyclizations and develop organocatalytic synthesizing indole derivatives. To fulfill this task, in work, by changing the alkynyl terminal substituent from t-Bu aryl group, reactivity 3-alkynyl-2-indolylmethanols is modulated serve as competent substrates Brønsted acid-catalyzed cyclization. Based on reactivity, first cyclization aryl-substituted with 2-naphthols accomplished, leading efficient construction a class axially chiral 3, 4-dihydrocyclopenta[b]indole scaffolds. This preliminary investigation asymmetric provides optional strategy atroposelective cyclopenta[b]indole addition, preparation optical purity established through resolution, which could complementary method catalytic approaches.

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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Development of Configurationally Labile Biaryl Reagents for Atropisomer Synthesis

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(28)

Published: May 16, 2024

Abstract Axially chiral biaryl scaffolds are important in pharmaceuticals, natural products, and asymmetric synthesis. Atroposelective ring‐opening of configurationally labile reagents via dynamic kinetic transformation provides a valuable approach to access axially atropisomers. This review summarizes seminal contributions recent advancements on this topic based the use different types reagents.

Language: Английский

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Atroposelective synthesis of biaxial bridged eight-membered terphenyls via a Co/SPDO-catalyzed aerobic oxidative coupling/desymmetrization of phenols

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: May 30, 2024

Abstract Bridged chiral biaryls are axially compounds with a medium-sized ring connecting the two arenes. Compared plentiful methods for enantioselective synthesis of biaryl compounds, synthetic approaches this subclass bridged atropisomers limited. Here we show an atroposelective 1,3-diaxial eight-membered terphenyl through Co/SPDO (spirocyclic pyrrolidine oxazoline)-catalyzed aerobic oxidative coupling/desymmetrization reaction prochiral phenols. This catalytic desymmetric process is enabled by combination earth-abundant Co(OAc) 2 and unique SPDO ligand in presence DABCO (1,4-diaza[2.2.2]bicyclooctane). An array diaxial terphenyls embedded azocane can be accessed high yields (up to 99%) excellent enantio- (>99% ee) diastereoselectivities (>20:1 dr).

Language: Английский

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Recent Advances in Catalytic Asymmetric Syntheses of Functionalized Heterocycles via Halogenation/Chalcogenation of Carbon‐Carbon Unsaturated Bonds

Advanced Synthesis & Catalysis, Journal Year: 2022, Volume and Issue: 364(23), P. 3974 - 4005

Published: Oct. 20, 2022

Abstract Halogen (fluorine, chlorine, bromine, iodine) or chalcogen (sulfur, selenium)‐containing heterocycles are widely recognized as key building blocks in many natural products and bioactive targets. Catalytic asymmetric halogenation/chalcogenation of carbon‐carbon unsaturated bonds via onium ion transformations efficient methods to obtain diverse chiral heterocyclic backbones. In the past few years, catalytic enantioselective versions halo/thio/seleno‐functionalizations with various halogen electrophiles have experienced constant development. This review highlights those advances preparing functionalized promoted by organocatalysts metal‐based catalysts. magnified image

Language: Английский

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Highlighting the Rich Chemistry of the Allenone Moiety

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(9), P. 1332 - 1384

Published: March 14, 2023

Abstract Conjugated and non‐conjugated allenones appear as recurring motifs in organic synthesis, natural products mechanistic investigations showing unique properties applications. The ability of to build cycles has provided a direct access strained systems, medium‐sized rings, arenes, heterocycles complex polycycles. In addition, have served models catalysis. critic compilation herein presented will provide an exhaustive overview the synthetic possibilities may offer, which certainly inspire our community their search more efficient methodologies, preparation biological pharmaceutical targets, improve knowledge theoretical chemistry. Great part this review discuss aspects, catalysis innovation insights chemical transformations implying allenone motif. many examples on total synthesis pharmacologically active compounds be described. We hope that attractive chemistry, catalysis, medicinal chemistry communities. magnified image

Language: Английский

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NHC-Catalyzed Chemo- and Enantioselective Reaction between Aldehydes and Enals for Access to Axially Chiral Arylaldehydes

Organic Letters, Journal Year: 2024, Volume and Issue: 26(4), P. 917 - 921

Published: Jan. 18, 2024

A chiral carbene-catalyzed chemo- and enantioselective reaction with racemic biaryl aldehydes α-bromoenals is developed for access to axially 2-arylbenzaldehydes through atroposelective dynamic kinetic resolution (DKR) processes. This DKR strategy can tolerate a broad scope of substrates diverse functionalities. The 2-aryl benzaldehyde products generally afford moderate good yields enantioselectivities. molecules afforded from the current approach are variable simple transformations functional excellent optical purities.

Language: Английский

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Organocatalytic Asymmetric Dearomative Spirocyclization/Oxa-Michael Addition Sequence: Synthesis of Polycyclic Tetralones

Organic Letters, Journal Year: 2024, Volume and Issue: 26(15), P. 3179 - 3183

Published: April 3, 2024

Herein, an organocatalytic asymmetric dearomative spirocyclization/oxa-Michael addition sequence with a newly designed substrate having two naphthol motifs has been developed. The reaction proceeds through in situ chiral vinylidene ortho-quinone methide (VQM) intermediate formation, spirocyclization of naphthol, and oxa-Michael reaction. densely functionalized tetralone products were formed high yields diastereo- enantioselectivities.

Language: Английский

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Torsional Strain‐Independent Catalytic Enantioselective Synthesis of Biaryl Atropisomers

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(43)

Published: Aug. 26, 2022

Catalytic asymmetric dynamic kinetic resolution of configurationally labile bridged biaryls is emerging as a powerful strategy for atropisomer synthesis. However, the reported examples suffer from an inherent challenge reactivity highly dependent on torsional strain biaryl substrates, which significantly narrows down scope and hampers application. Herein, we report our discovery development strain-independent reaction between thionolactones activated isocyanides. By employing auto-tandem silver catalysis, universal synthesis both tri- tetra-ortho-substituted thiazole-containing was realized in high yields with enantioselectivities. In addition, these products could be facilely converted to novel type bearing eight-membered lactone. Mechanistic studies were carried out elucidate cause this unusual reactivity.

Language: Английский

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Atroposelective Synthesis of 2‐Arylindoles via Chiral Phosphoric Acid‐Catalyzed Direct Amination of Indoles^†

Chinese Journal of Chemistry, Journal Year: 2023, Volume and Issue: 42(7), P. 731 - 735

Published: Nov. 29, 2023

Comprehensive Summary Indole‐based atropisomers are a very important class of axially chiral compounds. However, the atroposelective synthesis 2‐arylindole remains largely unexplored. In this study, we report successful atropisomeric 2‐arylindoles using direct amination indoles with p ‐quinonediimines in presence phosphoric acid as catalyst. Quinonediimine acts an aminating reagent through formal polarity inversion imine. The malonate group on 2‐aryl 2‐indoles was found to be essential for high enantioselectivity products. This could due additional interaction between ester and catalyst, well intramolecular hydrogen bonding. Our findings provide new strategy asymmetric construction atropisomers.

Language: Английский

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