The kinetics of Rh-catalyzed neohexene hydroformylation were investigated with the bulky monodentate ligand tris(2,4-di-tert-butylphenyl)phosphite. The hydrogenolysis of the Rh–acyl intermediate was identified as the rate-limiting step for both the linear and the branched aldehydes. Rate equations for both aldehydes were derived and kinetic parameters were estimated. Increased aldehyde linearity at higher temperatures, frequently observed in hydroformylation, was elucidated by deuterioformylation experiments. These showed that at 100 °C the formation of linear Rh–alkyl was more reversible than the formation of the branched derivative. The ratio of linear to branched Rh–acyl species was determined by in situ high-pressure IR spectroscopy experiments, which allowed the difference in the activation energies for the hydrogenolysis steps towards the aldehyde isomers to be quantified. The hydrogenolysis of Rh–acyl was found to be the step that caused the greatest temperature effect on the regioselectivity.

With regard to sustainability, carbon dioxide (CO₂) is an attractive C1 building block. However, due to thermodynamic restrictions, reactions incorporating CO₂ are relatively limited so far. One of the so-called “dream reactions” in this field is the catalytic oxidative coupling of CO₂ and ethene and subsequent β-H elimination to form acrylic acid. This reaction has been studied intensely for decades. However up to this date no suitable catalytic process has been established. Here we show that the catalytic conversion of ethene and CO₂ to acrylate is possible in the presence of a homogeneous nickel catalyst in combination with a “hard” Lewis acid. For the first time, catalytic conversion of CO₂ and ethene to acrylate with turnover numbers (TON) of up to 21 was demonstrated.

A slightly adapted catalyst system has been successfully applied in the direct amination of primary and secondary alcohols. Moreover, the applicability to diols has been shown, giving high selectivity towards the primary diamines. It was found that the Ru/P ratio as well as the amount of ammonia used are highly important in this system, especially for higher substrate loadings. The catalyst was employed on a larger batch scale for the conversion of isomannide to the corresponding diamine. Additionally, it was shown that the catalyst is stable for at least six consecutive runs. No significant loss of activity and selectivity was observed.