Ugi-Type Reaction Enables Access to Fused Imidazole Derivatives for DNA-Encoded Library Technology

This study presents a DNA-compatible synthesis of diverse N-fused imidazopyridines via a catalyst-free Ugi-type multicomponent reaction using TMSCN as a functional isonitrile equivalent. The desilylation activation occurs efficiently in water without additional catalysts. The method exhibits a broad substrate scope for aldehydes and heterocyclic amidines and excellent chemoselectivity, underscoring its utility for constructing privileged heteroaromatic scaffolds in DNA-encoded library technology.