Synthesis of 2,4- and 2,5-Disubstituted Oxazoles via Metal-Catalyzed Gross-Coupling Reactions

摘要

The rapid synthesis of 2,4- and 2,5-disub-stituted oxazoles via metal-catalyzed cross-coupling reactions is reported. The 4- or 5-position of the corresponding 4- or 5-halogenated 2-butylthiooxa-zoles was successfully functionalized via Suzuki-Miyaura, Sonogashira and Stille cross-coupling reactions. The 2-position of the 2-butylthiooxazoles obtained was further coupled to various organozinc reagents through palladium- or nickel-mediated cross-coupling reactions.