Reactions of 3‐Acylchromones with Heterocyclic Ketene Aminals: One‐Pot Synthesis and Phosphatase Inhibitory Activity of Fused Pyridine Derivatives

摘要

> Domino reactions of 3‐acylchromones, namely 3‐methoxalyl‐, 3‐aroyl‐ and 3‐cinnamoylchromones, with heterocyclic ketene aminals (HKAs) proceed by attack of the nucleophile on the C‐2 atom of the chromone moiety, pyrone ring‐opening and subsequent formal [3+3] cyclocondensation with formation of functionalized tetracyclic fused chromeno[2,3‐ b ]pyridines or 2 H ,3 H ‐imidazo[1,2‐ a ]pyridines. The product distribution depends on the type of acyl group located at the 3‐position of the chromone and on the size of the heterocyclic moiety of the HKAs. The products show considerable activity as selective phosphatase inhibitors.