Cobalt hydrocarbonyls phosphine-substituted

Table 5.2. Hydroformylation of propene in 2-ethylhexanol with phosphine-substituted cobalt hydrocarbonyl catalyst, HCo(CO)3Ph (Ph = organic phosphine) and synthesis gas of 2 1 H2-to-CO ratio at 50 atm and 130° C in semi-batch reactor.

Example 5.3. Hydroformylation of 1-pentene with phosphine-substituted cobalt hydrocarbonyl catalyst [2], Results of hydroformylation of 1-pentene in a semi-batch reactor are shown in Table 5.5. 

Example 6.5. Olefin hydroformylation with phosphine-substituted cobalt hydrocarbonyl catalyst [30], The pathway 6.9 of olefin hydroformylation with the "oxo" catalyst, HCo(CO)4, has been shown in Example 6.2 in Section 6.3. For phosphine-substituted catalysts, HCo(CO)3Ph (Ph = organic phosphine), the pathway olefin — aldehyde is essentially the same. However, these catalysts also promote hydrogenation of aldehyde to alcohol (Examples 7.3 and 7.4) and of olefin to paraffin (Example 7.5). Moreover, straight-chain primary aldehydes under the conditions of the reaction undergo to some extent condensation to aldol, which is subsequently dehydrated and hydrogenated to yield an alcohol of twice the carbon number (e.g., 2-ethyl hexanol from n-butanal see Section 11.2). The entire reaction system is... 

Practical examples include nitration of aromatics, olefin hydroformylation with cobalt hydrocarbonyls and phosphine-substituted hydrocarbonyls as catalysts, and ethyne dimerization. 

Example 7.5. Olefin hydrvformylation with paraffin by-product formation [7,9]. Hydroformylation of olefins to aldehydes, catalyzed by a phosphine-substituted cobalt hydrocarbonyl, HCo(CO)3Ph (Ph = tertiary organic phosphine), has been used for illustration in examples 5.2 and 5.3 in Sections 5.2 and 5.3. The catalyst also promotes hydrogenation, so aldehyde produced from olefin is converted to alcohol, and paraffin is formed from olefin as by-product ... 

Example 7.6. Olefin hydroformylation with phosphine-substituted cobalt hydrocarbonyl catalyst [7], The overall reaction system of olefin hydroformylation with a phosphine-substituted cobalt hydrocarbonyl catalyst to produce alcohol, paraffin, and a heavy alcohol has been shown in Example 6.5 (Section 6.5) ... 

Example 8.3. Phosphine-substituted cobalt hydrocarbonyls as hydroformylation catalysts. Extensively studied catalyst systems with complex equilibria include phosphine-substituted hydrocarbonyls of cobalt, HCo(CO)3Ph, where Ph stands for a tertiary organic phosphine. They are modifications of the original oxo catalyst, HCo(CO)4. Like the latter, they catalyze the oxo or hydroformylation reaction of olefins to aldehydes one carbon number higher ... 

Example 8.11. Hydrcformylation with phosphine-substituted cobalt hydrocarbonyl catalyst. The phosphine-substituted cobalt hydrocarbonyl catalyst used for hydro-formylation of olefins has been described in Section 8.2 (see network 8.13). The principal reaction... 

Examples include acetal hydrolysis, base-catalyzed aldol condensation, olefin hydroformylation catalyzed by phosphine-substituted cobalt hydrocarbonyls, phosphate transfer in biological systems, enzymatic transamination, adiponitrile synthesis via hydrocyanation, olefin hydrogenation with Wilkinson s catalyst, and osmium tetroxide-catalyzed asymmetric dihydroxylation of olefins. 

Example 11.1. Hydroformylation of cyclohexene with phosphine-substituted cobalt hydrocarbonyl catalyst. The most probable network of cyclohexene hydroformylation catalyzed by a phosphine-substituted cobalt hydrocarbonyl is shown on the facing page. HCo(CO)3Ph (cat) is in equilibrium with the CO-deficient HCo(CO)2Ph (cat ) and CO. For greater generality, quasi-equilibrium of these species with the 7r-complex, X, is not assumed. Actual hydroformylation olefin — aldehyde proceeds via a Heck-Breslow pathway (cycle 6.9 that includes the trihydride, X2) but without... 

Example 11.2. Streamlined network for hydroformylation of n-heptene catalyzed by phosphine-substituted cobalt hydrocarbonyl. In hydroformylation of straight-chain olefins with a phosphine-substituted cobalt hydrocarbonyl catalyst, the model must account for three complications that are absent with cyclohexene isomerization by migration of the double bond along the hydrocarbon chain, formation of isomeric aldehydes and alcohols, and condensation of the straight-chain aldehyde to "heavy ends (chiefly an alcohol of twice the carbon number, such as 2-ethylhexanol from propene via n-butanal and a C8 aldol). A streamlined network for n-heptene is ... 

Usually, the reactivity is highest for the terminal position and lowest for the positions at branches. Once the reactivities with regard to a specific reaction have been determined for all six positions, the reaction behavior of all types of monoolefins except those with strained rings or bulky substituents can be predicted with reasonable confidence. The reactivities of three structurally differed hexene isomers in hydroformylation catalyzed by phosphine-substituted cobalt hydrocarbonyls may serve as an example [16] ... 

Example 12.1. Hydroformylation of long-chain 1-olefins with phosphine-substituted cobalt hydrocarbonyl catalysts. Hydroformylation of long-chain 1-olefins with phosphine-substituted cobalt hydrocarbonyl catalysts provides a striking example of coupled parallel steps and the potential of an uncommon heat-transfer problem. The network is of the type 12.5 below, with the A, as the olefin isomers and the P, as the isomeric alcohol products (arrows represent multistep pathways see also Example 5.3, Figure 5.9, and network 5.43 in Section 5.3 and network 7.40 in Section 7.4). 

The example of the mass-transfer effect in olefin hydroformylation is interesting in still another respect. If a phosphine-substituted cobalt hydrocarbonyl is used as catalyst in combination with 1-olefin as reactant, a very strong burst of reaction ensues at the reactor inlet or at start of a batch reaction (see Example 12.1). 

Mass transfer can also affect the selectivity of a single, multistep reaction by altering the reactant ratios. An example is homogeneous liquid-phase hydro-formylation with phosphine-substituted cobalt hydrocarbonyl catalysts. Alcohol and paraffin byproduct are formed from olefin, H2, and CO. Mass transfer of CO is slower than that of H2, so that the H2 CO ratio in the liquid phase shifts in favor of H2. This causes more paraffin to be formed (see Example 7.5 in Section 7.3.2). 

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