Highly selective rhodium-catalyzed bis-hydroformylation of 1,7-octadiene to decanedial

The biphenol-based unsymmetrically substituted bisphosphite ligands were developed for the rhodium-catalyzed consecutive bis-hydroformylation of isolated dienes to linear dials. For the bis-hydroformylation of 1,7-octadiene to decanedial with L9, excellent chemoselectivity (up to 93 % dialdehyde yield) and regioselectivity (up to 17.6 l/b) were achieved with this catalytic system. The undesired isomerization of terminal alkene to internal alkene was effectively suppressed by regulating the steric hindrance of bisphosphite ligand, which was correlated with the variation of the percent buried volume (%V_bur) around the rhodium center.