Hydroformylations nonfunctionalized olefines

The kinetics of the new commercial process of hydroformylation of allyl alcohol was studied by Chaudhari in the temperature range from 60 to 80 °C [114]. The rate of reaction is first order in catalyst concentration and 1.5th order in hydrogen partial pressure. The dependence on p CO) does not differ from that observed in the hydroformylation of nonfunctionalized olefins. The reaction is retarded at higher substrate concentrations (> 1.25 mol/L). This substrate inhibition is not fully understood on the molecular level. The apparent activation energy for the oxo reaction of allyl alcohol was found to be 94 kJ/mol. 

The insertion of CO in the Pd-C bond to form an acylpalladium species can be supported by Co2(CO)g as co-catalyst [9]. This finding helped improve the chemoselectivity of the Pd-catalyzed hydroformylation of alkynes [10]. Under the conditions shown in Scheme 1.42, almost no hydrogenation products, such as saturated aldehydes or nonfunctionalized olefins, were formed. 

In bulk chemical processes, mainly nonfunctionalized olefins of different chain lengths are subjected as substrates to hydroformylation. Principally, terminal C=C bonds react faster than internal olefins. The rate of hydroformylation decreases with increasing steric hindrance of the substrate [1]. The following order was found independently of the metal used (Figure 4.1) [2] ... 

In 2013, Wong and Landis [26] investigated an asymmetric hydroformylation-(Wittig olefination) reaction of vinyl acetate by using a chiral catalyst based on (S,S,S)-BDP at 10bar (Scheme 5.136). After optimization, several other functionalized and nonfunctionalized olefins or 1,3-dienes could be converted under these conditions. 

The regioselective hydroformylation of functionalized and nonfunctionalized olefins can also be performed by platinum compounds [26] in chlorostannate ionic liquids as solvents for homogeneous catalysis (entries 20-22, Table 6.1). Dissolved in chlorostannate ionic liquids, the Pt catalyst shows enhanced stability and selectivity in the hydroformylation of methyl-3-pentenoate compared to the identical reaction in conventional organic solvents. The moderate Lewis acidity of these ionic liquids allows the activation of the Pt catalyst combined with tolerance of the functional groups in the substrate. In the case of 1-octene hydroformylation, a biphasic reaction system could be performed using the chlorostannate ionic liquid. 

With nonfunctionalized terminal olefins, the formation of internal olefins is favored. Less than 5% of the terminal olefins may be present in thermodynamic equilibrium. Slow isomerization in comparison to the subsequent hydroformylation may lead to a continuous erosion of the regioselectivity during the reaction [18]. -01efins are more stable than Z-isomers, therefore, double bond migration can commence with a Z/ -isomerization step [19]. 

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