Synthesis of beta-Isoxazole Carbonyl Derivatives and Their Analogues via Palladium-Catalyzed Sequential C(sp(2))-O/C(sp(2))-C(sp(3)) Bond Formations

摘要

An efficient Pd(II)-catalyzed one-pot tandem cyclization/alkylation reaction of internal alkynes has been reported. In this reaction, a wide range of structurally diverse beta/beta-isoxazole aldehydes/ketones could be obtained in good to excellent yields from various alkynyl oxime ethers and allylic or homoallylic alcohols. The gram-scale experiment and various transformations of the newly obtained products demonstrated that this method should be a general and useful synthetic tool.