Ag-Catalyzed Formal [2 + 4] Cycloaddition for the Diastereoselective Synthesis of Sterically Hindered 4-Aminochroman-2-ones from α-Diazopyrazoleamides and o-Hydroxy Aldimines.

Abstract

4-Aminochroman-2-one derivatives serve as crucial scaffolds in numerous pharmaceuticals and bioactive compounds. Here, we describe an efficient Ag-catalytic [2 + 4] cycloaddition reaction between α-diazo pyrazoleamides and o-hydroxy aromatic aldimines for the rapid synthesis of substituted 4-aminochroman-2-one derivatives with high yield and excellent diastereoselectivity. This method features a broad substrate scope, mild reaction conditions, and the ability to generate products exhibiting notable antitumor activity against selected tumor cell lines.