Cascade Alkynyl Prins Cyclization and Aza-Michael Reaction: En Route to Regioselective Pyrano- and Isochromenoquinoline Scaffolds DOI
Subhamoy Biswas, Anil K. Saikia

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

Published: Sept. 20, 2024

A metal-free, Lewis acid approach for the regioselective synthesis of dihydropyranoquinoline scaffolds has been unveiled. The methodology employs a cascade alkynyl Prins-aza-Michael reaction sequence to deliver products in good excellent yields. strategy features mild conditions, broad substrate scope, and high functional group tolerance. protocol further extended include isochromenoquinoline derivatives. utility lies highly fused polycyclic N,O-heterocycles via intramolecular Heck coupling. Additionally, Rh(III)-catalyzed annulation results formation fluorescent pentacyclic ammonium salts Photophysical studies reveal that these exhibit strong emission green region (500-550 nm).

Language: Английский

Phosphine‐Catalyzed Divergent γ,γ‐ and ε,γ‐Umpolung Domino Additions of Bisoxindoles with Allenoates: Construction of Vicinal All‐Carbon Quaternary Stereocenters and Formal Total Synthesis of Dimeric Cyclotryptamine Alkaloids DOI Open Access
Yufei Zhang, Jing Chen, Hui Yao

et al.

Chinese Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 25, 2025

Comprehensive Summary Vicinal all‐carbon quaternary stereocenters are widely present in natural products and bioactive molecules. However, the construction of such motif one step from readily available starting materials remains a significant challenge. Herein, we report phosphine‐catalyzed divergent γ,γ‐ ε,γ‐umpolung domino addition bisoxindoles with allenoates. This method serves as practical tool for concise synthesis series bisoxindole derivatives bearing sterically hindered vicinal under mild reaction conditions. The applicability this novel was demonstrated gram‐scale three known advanced intermediates total syntheses calycanthine, chimonanthine folicanthine.

Language: Английский

Citations

2
Phosphine-Catalyzed Cascade Cycloaddition of Vinyl Oxiranes with Sulfonium Compounds to Step-Economically Construct Spiro-2(3H)-furanone Scaffolds DOI
Thomas P. Yang, Wei Du,

Chia‐Yu Wu

et al.

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

Published: Jan. 9, 2025

In this work, we developed a phosphine-catalyzed cascade lactonization/[2 + 1] annulation reaction between vinyl oxiranes and sulfonium compounds for the highly diastereoselective construction of spiro-2(3H)-furanone skeletons. The cycloaddition proceeds via 2(5H)-furanone phosphonium intermediate, introducing an oxygen-containing active intermediate phosphine catalysis. These findings highlight significant potential harnessing as versatile synthons constructing spirocyclic through simultaneous multicyclic skeleton formation.

Language: Английский

Citations

0
Recent advances in phosphine-mediated sequential annulations DOI

Xuling Pan,

Wei Cai, You Huang

et al.

Chinese Chemical Letters, Journal Year: 2024, Volume and Issue: unknown, P. 110628 - 110628

Published: Nov. 1, 2024

Language: Английский

Citations

1
DMAP-Catalyzed [4 + 2] Annulation of Hex-5-en-2-ynoates with Electron-Poor Alkenes DOI

Dongqiu Li,

Jiale Wu, Lulu Yang

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 20, 2024

Herein, we report a DMAP-catalyzed [4 + 2] annulation reaction of hex-5-en-2-ynoates 1 with electron-poor alkenes 2, which affords exocyclic olefinic cyclohexenes 3 in good yields and excellent regio-, diastereo-, E/Z selectivities. Distinguished from previous allenoate- or alkynoate-based substrates, use the β- ε-carbons for bond formation, presenting new regiodivergent C4 synthons Lewis base-catalyzed annulations.

Language: Английский

Citations

0
Cascade Alkynyl Prins Cyclization and Aza-Michael Reaction: En Route to Regioselective Pyrano- and Isochromenoquinoline Scaffolds DOI
Subhamoy Biswas, Anil K. Saikia

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

Published: Sept. 20, 2024

A metal-free, Lewis acid approach for the regioselective synthesis of dihydropyranoquinoline scaffolds has been unveiled. The methodology employs a cascade alkynyl Prins-aza-Michael reaction sequence to deliver products in good excellent yields. strategy features mild conditions, broad substrate scope, and high functional group tolerance. protocol further extended include isochromenoquinoline derivatives. utility lies highly fused polycyclic N,O-heterocycles via intramolecular Heck coupling. Additionally, Rh(III)-catalyzed annulation results formation fluorescent pentacyclic ammonium salts Photophysical studies reveal that these exhibit strong emission green region (500-550 nm).

Language: Английский

Citations

0