3656. WENDER, I., ORCHIN, M, AND STORCH, H. H. New Modifications of the Oxo Process. Armed Forces Chem. Jour., vol. 4, October 1950, pp. 4-9.
It is pointed out, with reference to the work of Keulemans, Kwantes, and Van Bavel (abs. 1739), that it is possible by the hydroformylation of olefins to predict the structure of the aldehydes or alcohols obtained from a given olefin. It also has been found that under regulated conditions of pressure and temperature it is entirely feasible to produce alcohols from olefins by a 1-step synthesis or to isolate the aldehyde as the major product. It is indicated quite strongly as the result of experiments that hydrogenation reactions that occur in the presence of Co and a high partial pressure of CO proceed by homogeneous catalysis in which dicobalt octacarbonyl functions as the catalyst. It also is possible that the reductions that occur under Oxo conditions proceed via a free radical mechanism. If this is so, hydrogenation under such conditions should not be adversely affected by S compounds, as is the heterogeneous catalysis of hydrogenation over a solid catalyst. Under the conditions of the Oxo reaction, some types of unsaturated linkages are hydrogenated, whereas others react by hydroformylation. Several such reactions are described, and the yields of products obtainable are summarized. Of particular interest is the reaction of furan and its derivatives. The homologation of aliphatic alcohols and the hydrogenation and homologation of aromatic aldehydes, ketones, and alcohols are discussed. It is not yet proved, but it is assumed, that the Oxo reaction with olefins proceeds via a carbonium ion, and evidence is mounting that homologation may proceed through such an intermediate. Two recently discovered reactions are found to take place under Oxo conditions: HCHO reacts with synthesis gas to yield ethylene glycol and methylal with synthesis gas, and a Co catalyst yields methyl cellosolve. The synthesis of EtOH from coal or natural gas via synthesis gas and MeOH now is possible. Recent work indicates that EtOH may be an intermediate in the Fischer-Tropsch synthesis. Further assumptions have been made as to the possible mechanism of the Fischer-Tropsch hydrocarbon synthesis: The C skeleton is built up by the stepwise addition of 1 C atom at a time, and addition of the C atom occurs only at the terminal or next to the terminal C atom of the chain and does not occur at a tertiary C atom to form a product containing a quarternary C atom. As regards the Oxo synthesis these assumptions are already accepted as facts.
WENDER, I., ORCHIN, M., AND STORCH, H. H. Mechanism of the Oxo and Related Reactions. III. Evidence for Homogeneous Hydrogenation. See abs. 3654.