Synthesis of gold allyloxysulfonium complexes and elimination to form an α,β-unsaturated aldehyde

Abstract

Treatment of the gold vinyl carbene/allylic cation complex (E)-[(IPr)AuC(H)C(H)C(4-C₆H₄OMe)₂]⁺ OTf⁻ with sulfoxides at −95 °C formed the corresponding gold allyloxysulfonium complexes [(IPr)AuC(H)(OSR₂)C(H)C(4-C₆H₄OMe)₂]⁺ OTf⁻ [R = Me, –(CH₂)₄–, Ar] in ≥95 ± 5% NMR yield. Allyloxysulfonium gold complexes underwent elimination at or below room temperature to form 3,3-bis(4-methoxyphenyl)acrylaldehyde in ≥67% yield.