Synthesis of fused hydroxy dihydropyrroles and unexpected dihydropyrazine and dihydroquinoxaline derivatives based on heterocyclic ketene aminals

摘要

The one-pot four-component synthesis of highly functionalized fused hydroxyl dihydropyrroles and dihydropyrazines from readily available diamines, 1,1-bis (methylsulfanyl)-2-nitroethene, phenylglyoxal monohydrates, and C-H acids have been developed. This strategy provides an efficient, catalyst-free approach for easy access to various new hydroxyl-dihydropyrrole and dihydropyrazine rings in good to high yields. The products were confirmed by H-1 and C-13 NMR, IR, mass, and X-ray crystal structure analyses.