Rhodium-Catalyzed Hydroformylation of Cyclic Alkenes Using Bisphenol-A Derived Bisphosphine Ligands: Dicyclopentadiene as a Key Substrate

Rhodium-catalyzed hydroformylation of dicyclopentadiene (DCPD) is an industrially attractive process to produce dialdehydes where developing cheap and highly selective catalysts remains an important subject. In this contribution, we analyzed the efficiency of easily accessible bisphosphine ligands based on readily available bisphenol-A in Rh-catalyzed hydroformylation of DCPD. Two bisphosphine ligands (L1 and L2) and one monophosphine ligand (L3) were prepared and applied as ligands in the Rh-catalyzed hydroformylation of DCPD. By careful optimization of temperature, syngas pressure and reaction time, the catalyst Rh/L1 demonstrated excellent activity and selectivity, achieving 100% substrate conversion, up to 405 Turnover Numbers (TONs) and 81% dialdehyde selectivity under mild operating conditions (30 bar syngas, 80°C). The optimized catalyst can also convert DCPD to useful dialdehyde at 5 grams scale and as well actively hydroformylate cyclopentene, cyclohexene and 2,3-dihydrofuran to the corresponding useful aldehydes.