A green metal-free “one-pot” microwave assisted synthesis of 1,4-dihydrochromene triazoles
作者:Tânia M. F. Alves、Guilherme A. M. Jardim、Marco A. B. Ferreira
DOI:10.1039/d1ra01169c
日期:——
The synthesis of several 4-aryl-1,4-dihydrochromene-triazoles was achieved via a metal-free “one-pot” procedure using PEG400 as the sole solvent in an eco-friendly process. Using microwave irradiation, the triazole derivatives were obtained in good yields and short reaction times starting from readily accessible building blocks.
The 1,3-dipolar cycloaddition of 2-aryl-3-nitrochromenes with various azomethine ylides has been investigated. The structure and stereochemistry of cycloadducts were studied in detail by NMR spectroscopic methods.
Cascade oxa-Michael-Henry reactions of salicylaldehyde derivatives with beta-nitrostyrenes catalyzed by potassium carbonate via solvent-free ball milling are demonstrated. The corresponding 3-nitro-2H-chromene products were obtained in moderate to excellent yields. This method offers significant advantages, particularly in terms of high yields, short reaction times and mild conditions.
3-Nitrochromene derivatives as 2π components in 1,3-dipolar cycloadditions of azomethine ylides
The 1,3-dipolar cycloaddition of 2-aryl-3-nitrochromenes with various azomethine ylides has been investigated. The structure and stereochemistry of cycloadducts were studied in detail by NMR spectroscopic methods. (c) 2006 Elsevier Ltd. All rights reserved.