Alkoxydienylstannanes viametalation of α,β-unsaturated and α-phenyl acetals: preparation and synthetic uses in the Stille cross-coupling reaction

Abstract

Treatment of α,β-unsaturated (1 and 2) and α-phenyl (3) acetals with an equimolar mixture of butyllithium and potassium tert-butoxide (Schlosser’s reagent LIC–KOR) gives α-metalated 1,3-dienes and vinyl ethers that readily react with chlorotributyltin affording (Z)-functionalized alkoxyvinylstannanes 4–6. Stille cross-coupling reaction between these reactants and allyl bromide, iodobenzene, or benzoyl chloride produces derivatives 7–13 that can be moreover converted into carbonyl compounds 14–19 according to an umpolung approach.