Rh-catalyzed hydroformylation of butadiene to adipaldehyde is a promising alternative route for producing valuable C₆ compounds such as adipic acid and hexamethylenediamine. Fundamental insights into reaction pathways, aimed at enhancing adipaldehyde yield, were obtained from temporal concentration profiles and in situ ReactIR studies of butadiene hydroformylation on Rh complexes at 80 °C and 14 bar syngas (molar CO/H₂ = 1) pressure in a batch reactor. Specifically, the effects of operating conditions and eight commercially available ligands on activity and selectivity were systematically investigated. It was found that the adipaldehyde selectivity is independent of the ligand/Rh ratio, rhodium concentration, butadiene concentration and syngas pressure, but significantly dependent on the type of ligand used. For example, while the DIOP ligand provided an adipaldehyde yield of ∼40% with butadiene as a substrate, the 6-DPPon ligand gave a maximum adipaldehyde yield of ∼93% with 4-pentenal as substrate. Furthermore, the adipaldehyde selectivity correlates well with the natural bite angle of the various ligands. ReactIR studies suggest that the preferential formation of the stable rhodium η³-crotyl complex with the various Rh complexes may be the main reason for the low adipaldehyde selectivity.

丁二烯经Rh催化加氢甲酰化成己二醛是生产有价值的C ₆化合物（如己二酸和六亚甲基二胺）的有前途的替代途径。在80°C和14 bar合成气（CO / H ₂摩尔比）下，从时间浓度分布图和在Rh配合物上丁二烯加氢甲酰化的原位ReactIR研究获得了旨在提高己二醛收率的反应途径的基本见解。 = 1）分批反应器中的压力。具体而言，系统地研究了操作条件和八种市售配体对活性和选择性的影响。发现己二醛的选择性与配体/ Rh比，铑浓度，丁二烯浓度和合成气压力无关，但显着取决于所用配体的类型。例如，当DIOP配体以丁二烯为底物可提供约40％的己二醛产率，而6-DPPon配体以4-戊烯为底物可提供约93％的最大己二醛产率。此外，己二醛的选择性与各种配体的自然咬合度密切相关。的ReactIR研究表明，优先形成稳定的铑η ³-巴豆基配合物与各种Rh配合物可能是导致己二醛选择性低的主要原因。