Libraries of C‐5 Substituted Imidazoles and Oxazoles by Sequential Van Leusen (VL)–Suzuki, VL–Heck and VL–Sonogashira in Imidazolium‐ILs with Piperidine‐Appended‐IL as Base.

Facile access to diverse C5‐substituted imidazoles and oxazoles via sequential Van Leusen–Suzuki, Van Leusen–Heck, and Van Leusen–Sonogashira protocols, employing imidazolium‐ILs as solvents along with piperidine‐appended imidazolium [PAIM][NTf2] as task‐specific basic IL has been demonstrated, in a high‐yielding one‐pot method, starting with readily available aldimines (for imidazole) or aldehydes (for oxazole) and tosylmethylisocyanide (Tos‐MIC), under mild conditions with potential for recycling and reuse of the IL solvent. The scope of the method is supported 49 examples. By sequencing the Van Leusen imidazole and oxazole syntheses with Suzuki, Heck and Sonogashira reactions, diverse libraries of C5‐functionalized imidazoles and oxazoles were synthesized in one‐pot reactions employing [BMIM][X] as a solvent and [PAIM][NTf2] as a base. [ABSTRACT FROM AUTHOR]