Bronsted Acid-Catalyzed Three-Component 1,3-Dipolar Cycloadditions of 1,2-Disubstituted Alkynes with Aldehyde-Generated Azomethine Ylides

摘要

The first 1,3-dipolar cycloadditions (1,3-DCs) of 1,2-disubstituted alkynes with aldehyde-generated azomethine ylides have been established, leading to the efficient synthesis of poly-substituted 2,5-dihydropyrroles. The Bronsted acid-catalyzed three-component 1,3-DCs of but-2-ynedioates, aldehydes, and diethyl 2-aminomalonate tolerate a wide range of substrates, offering structurally diverse poly-substituted 2,5-dihydropyrroles in high yields. This protocol not only provides an easy and efficient approach to poly-substituted 2,5-dihydropyrroles but also greatly enriches the chemistry of 1,3-DCs, especially alkyne-involved 1,3-DCs.