Hydroformylation process
A catalyst, useful for the hydroformylation of allyl alcohol, is described. The catalyst comprises a rhodium complex and a 6-bis(3,5-dialkylphenyl)phosphino-N-pivaloyl-2-aminopyridine or a 3-bis(3,5-dialkylphenyl)phosphino-2H-isoquinolin-1-one. The invention also includes a process for the production of 4-hydroxybutyraldehyde comprising reacting allyl alcohol with a mixture of carbon monoxide and hydrogen in the presence of a solvent and the catalyst. The process gives a high ratio of the linear product 4-hydroxybutyraldehyde to the branched co-product 3-hydroxy-2-methylpropionaldehyde.
1. A process to produce 4-hydroxybutyraldehyde comprising reacting allyl alcohol with carbon monoxide and hydrogen in the presence of a solvent and a catalyst comprising a rhodium complex and a phosphine selected from the group consisting of a 6-bis(3,5-dialkylphenyl)phosphino-N-pivaloyl-2-aminopyridine and a 3-bis(3,5-dialkylphenyl)phosphino-2H-isoquinolin-1-one.
2. The process of claim 1 wherein the phosphine is 6-bis(3,5-dimethylphenyl)phosphino-N-pivaloyl-2-aminopyridine.
3. The process of claim 1 wherein the phosphine is 3-bis(3,5-dimethylphenyl)phosphino-2H-isoquinolin-1-one.
4. The process of claim 1 wherein the phosphine is a mixture of the 6-bis(3,5-dialkylphenyl)phosphino-N-pivaloyl-2-aminopyridine and a 3-diarylphosphino-2H-isoquinolin-1-one.
5. The process of claim 1 wherein the phosphine is a mixture of the 3-bis(3,5-dialkylphenyl)phosphino-2H-isoquinolin-1-one and a 6-diarylphosphino-N-pivaloyl-2-aminopyridine.
6. The process of claim 1 wherein the solvent is selected from the group consisting of C 5 -C 20 aliphatic hydrocarbons, C 6 -C 12 aromatic hydrocarbons, ethers, alcohols, and mixtures thereof.
7. The process of claim 1 wherein the solvent is selected from the group consisting of toluene, cyclohexane, methyl t-butyl ether, isopropanol, and mixtures thereof.
8. The process of claim 1 wherein the rhodium complex comprises rhodium and ligands selected from the group consisting of hydride, carbonyl, trialkyl phosphines, triaryl phosphines, diphosphines, cyclopentadienyls, 2,4-alkanedionates, and mixtures thereof.
9. The process of claim 1 further comprising hydrogenating the 4-hydroxybutyraldehyde in the presence of a hydrogenation catalyst to form 1,4-butanediol.
10. A catalyst comprising a rhodium complex and a phosphine selected from the group consisting of a 6-bis(3,5-dialkylphenyl)phosphino-N-pivaloyl-2-aminopyridine and a 3-bis(3,5-dialkylphenyl)phosphino-2H-isoquinolin-1-one.
11. The catalyst of claim 10 which comprises the rhodium complex and 6-bis(3,5-dimethylphenyl)phosphino-N-pivaloyl-2-aminopyridine.
12. The catalyst of claim 10 which comprises the rhodium complex and 3-bis(3,5-dimethylphenyl)phosphino-2H-isoquinolin-1-one.
13. The catalyst of claim 10 which comprises the rhodium complex and a mixture of the 6-bis(3,5-dialkylphenyl)phosphino-N-pivaloyl-2-aminopyridine and a 3-diarylphosphino-2H-isoquinolin-1-one.
14. The catalyst of claim 10 which comprises the rhodium complex and a mixture of the 3-bis(3,5-dialkylphenyl)phosphino-2H-isoquinolin-1-one and a 6-diarylphosphino-N-pivaloyl-2-aminopyridine.