A hydroformylation process for preparing dialdehydes from dienes by contacting a C.sub.6 -C.sub.10 diene in a reaction zone at a temperature of from about 20.degree. C. to about 250.degree. C. and a pressure of from about 15 psig to about 800 psig with hydrogen, carbon monoxide, and a catalyst containing rhodium, the ligand having the formula ##STR1## wherein: n is 1-4; each R is independently selected from hydrogen, alkyl, alkoxy, aryloxy, aryl, aralkyl, alkaryl, alkoxyalkyl, cycloaliphatic, halogen, alkanoyl, alkanoyloxy, alkoxycarbonyl, carboxyl or cyano; each R.sub.1 and R.sub.2 is independently selected from alkyl, aryl, aralkyl, alkaryl or cycloaliphatic; each R.sub.3 and R.sub.4 is independently selected from hydrogen and the R.sub.1 substituents; and each Y is independently selected from the elements N, P, As, Sb and Bi.
The method for producing .alpha.,.omega.-dialdehydes from .alpha.,.omega.-diolefins or .alpha.,.omega.-alkenals in good yield and with high efficiency. The expensive rhodium catalyst for hydroformylation can be reused without any substantial attrition of activity. Moreover, since the loses of the catalyst, monodentate phosphine and sulfolane used in the hydroformylation reaction are minimal, the method is commercially advantageous.
The hydroformylation of olefins and olefinically unsaturated compounds in the presence of a water-soluble rhodium complex compound Which contains, as a ligand, at least one sulfonated diphosphine, and a catalyst therefor.
A process is disclosed for preparing aldehydes by isomerization of the corresponding unsaturated primary alcohols using a transition metal catalyst system, in an alcoholic solvent and in the presence of an acid. An aldehyde forms by isomerizing an unsaturated primary alcohol under conditions that protect the newly formed aldehyde as a dialkylacetal in situ during the reaction. Protecting the aldehyde as an acetal allows for facile separation of the product from the catalyst as well as effectively driving the reaction toward completion.
Disclosed is a process for the preparation of 3-methyltetrahydrofuran (3-MeTHF) which comprises contacting 3-formyltetrahydrofuran with hydrogen in the presence of a catalyst system comprising a Group VIII noble metal or rhenium and a strong acid under hydrogenolysis conditions of temperature and pressure to produce 3-MeTHF. The 3-MeTHF produced in accordance with the present invention is useful as an industrial solvent and, more importantly, as a monomer in the manufacture of polymers such as elastomers.
This invention relates to a hydroformylation process for producing a 1,6-hexanedial which comprises reacting a butadiene with hydrogen and carbon monoxide in the presence of a catalytic amount of rhodium complexed with certain poly-phosphite ligands to achieve high conversions of the butadiene to the 1,6-hexanedial.
