Novel spiroketal-based diphosphite ligands for hydroformylation of terminal and internal olefins

Spiroketal-based diphosphite ligands have been developed for the rhodium-catalyzed hydroformylation reaction. Under the optimized reaction conditions, a turnover number (TON) of up to 2.4 x 10(4) and a linear to branched ratio (l/b) of up to 93 were obtained in the hydroformylation of terminal olefins. The catalysts were also found to be effective in the isomerization-hydroformylation of some internal olefins.