Homogeneous catalytic hydroaryloxycarbonylation of 2-allylphenol derivatives was performed using palladium complexes toward the corresponding lactones. Reactions were conducted under carbon monoxide atmosphere in the absence of hydrogen gas. Palladium catalyst was generated in situ, using various phosphine ligands and precursors in the presence of acid additives. In general, chiral 6- and achiral 7-membered lactones were formed dominantly, only trace amounts of the 5-membered lactone can be identified. Moderate or good enantioselectivity can be achieved using chiral ligands regarding the 6-membered chromanone derivatives. The regioselectivity of the reaction is particularly effected by catalyst composition and acid co-catalysts, and found to be insensitive for substrate substitution.
- Carbon monoxide
ASJC Scopus subject areas
- Process Chemistry and Technology
- Physical and Theoretical Chemistry