Alkoxides as Nucleophiles in (?-Allyl)palladium Chemistry. Synthetic and Mechanistic Studies

Article abstract of DOI:10.1021/ja00345a050

A new methodology for the use of alkoxides as nucleophiles in (?-allyl)palladium chemistry has been developed.In this process an allylic alcohol serves as the precursor to the ?-allyl complex and a triethylsilyl (TES) ether as precursor to the alkoxide nucleophile.By using Pd(PPh3)4 in CCl4, PPh3Cl⁺CCl3^- is generated transposing the ROH into an oxyphosphonium group, R-O-P⁺Ph3, and liberating Cl^-.The Cl deprotects the TES ether, providing the nucleophile in situ.Application of this reaction to the preparation of a variety of furans is discussed.This process was determined to proceed with overall predominant retention of configuration.Mechanistic studies suggest a small energy difference between attack by alkoxide on the allyl ligand of the intermediate complex and attack on the metal, followed by reductive elimination.