Photocatalytic One-Pot Three-Component Reaction for the Regioselective Synthesis of Bromo-Substituted Pyrazoles

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(22), P. 16809 - 16827

Published: Nov. 1, 2024

A photocatalytic three-component cascade reaction of readily available enaminones, hydrazines, and CBr4 for the synthesis bromo-substituted pyrazoles in one pot has been demonstrated. This strategy involves intermolecular C-N/C-Br bond formation represents an efficient approach to construction 4-bromo-substituted with high regioselectivity, broad substrate scope, good functional group tolerance, convenient operation, mild conditions. Mechanistic investigations show that this proceeds via cyclization enaminones followed by a regioselective bromination using as "Br" source.

Language: Английский

Halogen Radical-Enabled Dearomatization of N-Arylpropiolamides via Photoinduced Sequential Halogenation/Spirocyclization/Oxidation Process

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

Published: Dec. 4, 2024

Here we report a strategy that eliminates the need for photocatalysts and external additives, which provides an operable mild method halogen radical-enabled dearomatization of N-arylpropiolamides under oxygen atmosphere at room temperature. The is applicable to wide range substrates, extending beyond limited scope p-methoxyl N-phenylpropynamides. Furthermore, several functional synthetic intermediates anticancer bioactive molecules were successfully derived from 3-halogenated azaspiro[4.5]trienones.

Language: Английский