Highly selective and recyclable homogeneous hydroformylation of olefins with [Rh(cod)Cl]2/PPh3 regulated by Et3N as additive

• Rh-catalyzed high chemo/regioselectivity hydroformylation regulated by additive Et 3 N. • Recyclable homogeneous hydroformylation reaction without solvent involved. • Wide substrates scope including the production of pesticide and perfume intermediates. Rh-catalyzed hydroformylation of different olefins toward the corresponding aldehydes were performed under syngas atmosphere in the presence of triethylamine (Et 3 N) as additive. The influence of various reaction parameters including the phosphine ligands, solvents, additives have been investigated. It was found that, by involving Et 3 N as additive in the [Rh(cod)Cl] 2 /PPh 3 catalytic system, the conversion of substrates (including cyclic, internal and linear olefins, up to 99%) and chemo/regioselectivity of the products were improved (up to 99%), the applicability for the synthesis of important aldehydes was wider in the absence of solvent. More importantly, the catalytic system could be recycled more than 7 times through vacuum distillation operation and provided a new synthesis method for the pesticide dinotefuran (Tetrahydrofuran-3-formaldehyde) and perfume (Lily aldehyde) intermediates.