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, Год журнала: 2024, Номер unknown

Опубликована: Сен. 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).

Язык: Английский

Formal Dehydrative [3+2] Annulation of N‐Arylhydroxamine and Activated Alkyne Toward Indole DOI

Xiaoyan Hong,

Lanqin Liu,

Huaguang Yu

и другие.

Asian Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Май 20, 2025

Abstract An efficient approach for the synthesis of indole by annulation N ‐substituted hydroxylamine with activated alkynes under mild reaction conditions was established without additional catalyst or chemical reagents. Both 3‐substituted and 2,3‐disubstituted indoles were obtained good‐to‐excellent isolated yields using terminal internal electron‐deficient alkynes, respectively. This novel green protocol provides a rapid, mild, method construction heterocycles.

Язык: Английский

Процитировано

0

Iron-Catalyzed [3 + 2] Annulation of O-Acyl Oximes with 2-Hydroxy-1-Naphthoates for the Synthesis of Benzo[g]indoles DOI
Zhen Cui, Hui Li,

Xian-Heng Ding

и другие.

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Май 28, 2025

An iron-catalyzed [3 + 2] annulation of O-acyl oximes with 2-hydroxy-1-naphthoates has been developed. This strategy features the simultaneous activation both substrates to form two radical intermediates. Subsequent selective C-N coupling followed by sequential condensation and 1,3-ester migration affords 1H- or 3H-benzo[g]indoles. In terms derived from 4-oxocyclohexanone 4-azacyclohexanone, further ring-opening furnishes 2-(2-hydroxyethyl)- 2-(2-aminoethyl)-1H-benzo[g]indoles.

Язык: Английский

Процитировано

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, Год журнала: 2024, Номер unknown

Опубликована: Сен. 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).

Язык: Английский

Процитировано

0