Patent EA-000498-B1 (EA)
Title: Process for the hydrogeneration of imines
Inventor: JALETT HANS-PETER
IPC: B01J31/02
Filed: 1996-06-04
Abstract: 1. A process for the hydrogenation of an imine with hydrogen under elevated pressure in the presence of an iridium catalyst and with or without an inert solvent, wherein the reaction mixture contains hydrogen iodide. 2. A process according to Claim 1, wherein the imine contains at least one >=N-group. 3. A process according to Claim 1, wherein the imine contains at least one of the groups >C=N- and >C=N-N- and additionally unsaturated groups >C=C< and >C=O. 4. A process according to Claim 3, wherein the free bonds are saturated with hydrogen or organic radicals having from 1 to 22 carbon atoms or organic hetero radicals having from 1 to 20 carbon atoms and at least one hetero atom from the group O, S, N and P; or the nitrogen atom of the group >C==N- is saturated with NH2 or a secondary amino group having from 2 to 40 carbon atoms. 5. A process according to Claim 1, wherein an aldimine, ketimine or hydrazone is hydrogenated. 6. A process according to Claim 5, wherein the imine is an imine of formula I   which is hydrogenated to form an amine of formula II   wherein R3 is linear or branched C1-C12alkyl, cycloalkyl having from 3 to 8 ring carbon atoms; heterocycloalkyl bonded via a carbon atom and having from 3 to 8 ring atoms and 1 or 2 hetero atoms from the group O, S and NR6; a C7-C16 aralkyl bonded via an alkyl carbon atom, or C1-C12alkyl substituted by the mentioned cycloalkyl or heterocycloalkyl or heteroaryl; or wherein R3 is C6-C12 aryl, or C4-C11 heteroaryl bonded via a ring carbon atom and having 1 or 2 hetero atoms in the ring; R3 being unsubstituted or substituted by -CN, -NO2, F, Cl, C1-C12 alkyl, C1-C12 alkoxy, C1-C12 alkylthio, C1-C6 haloalkyl, -OH, C6-C12 aryl or -aryloxy or -arylthio, C7-C16-aralkyl or -aralkoxy or -aralkylthio, secondary amino having from 2 to 24 carbon atoms, -CONR4R5 or by -COOR4, and the aryl radicals and the aryl groups in the aralkyl, aralkoxy and aralkylthio in turn being unsubstituted or substituted by -CN, -NO2, F, Cl, C1-C4-alkyl, -alkoxy or -alkylthio, -OH, -CONR4R5 or by -COOR4; R4 and R5 are each independently of the other hydrogen, C1-C12 alkyl, phenyl or benzyl, or R4 and R5 together are tetra- or pentamethylene or 3-oxapentylene; R6 has independently the same meaning as given for R4; R1 and R2 are each independently of the other a hydrogen atom, C1-C12 alkyl or cycloalkyl having from 3 to 8 ring carbon atoms, each of which is unsubstituted or substituted by -OH, C1-C12 alkoxy, phenoxy, benzyloxy, secondary amino having from 2 to 24 carbon atoms, -CONR4R5 or by -COOR4; C6-C12 aryl or C7-C16 aralkyl that is unsubstituted or substituted as R3, or -CONR4R5 or -COOR4, wherein R4 and R5 are as defined hereinbefore; or R3 is as defined hereinbefore and R1 and R2 together are alkylene having from 2 to 5 carbon atoms that is optionally interrupted by 1 or 2 -O-, -S- or -NR6- radicals, and/or unsubstituted or substituted by =O or as R1 and R2 above in the meaning of alkyl, and/or condensed with benzene, pyridine, pyrimidine, furan, thiophene or pyrrole; or R2 is as defined hereinbefore and R1 and R3 together are alkylene having from 2 to 5 carbon atoms that is optionally interrupted by 1 or 2 -O-, -S- or -NR6- radicals, and/or unsubstituted or substituted by =O or as R1 and R2 above in the meaning of alkyl, and/or condensed with benzene, pyridine, pyrimidine, furan, thiophene or pyrrole. 7. A process according to Claim 5, wherein R1 and R2 as heteroaryl form a 5- or 6-membered ring having 1 or 2 identical or different hetero atoms. 8. A process according to Claim 5, wherein R1 and R2 as heteroaryl-substituted alkyl are derived from a 5- or 6-membered ring having 1 or 2 identical or different hetero atoms. 9. A process according to Claim 5, wherein R1 and R2 as heterocycloalkyl or as heterocycloalkylsubstituted alkyl contain from 4 to 6 ring atoms and 1 or 2 identical or different hetero atoms from the group O, S and NR6, wherein R6 is hydrogen, C1-C12 alkyl, phenyl or benzyl. 10. A process according to Claim 5, wherein R1, R2 and R3 as alkyl are unsubstituted or substituted C1-C6 alkyl. 11. A process according to Claim 5, wherein R1, R2 and R3 as unsubstituted or substituted cycloalkyl contain from 3 to 6 ring carbon atoms. 12. A process according to Claim 5, wherein R1, R2 and R3 as aryl are unsubstituted or substituted naphthyl or phenyl, and R1, R2 and R3 as aralkyl are unsubstituted or substituted phenylalkyl having from 1 to 10 carbon atoms in the alkylene. 13. A process according to Claim 5, wherein R1 and R2 together or R1 and R3 together form, with the carbon atom or with the -N=C group to which they are bonded, respectively, a 5- or 6-membered ring. 14. A process according to Claim 5, wherein in formula I R3 is 2,6-di-C1-C4 alkylphen-l-yl, R1 is C1-C4 alkyl, and R2 is C1-C4 alkyl, C1-C4 alkoxymethyl or C1-C4alkoxyethyl. 15. A process according to Claim 14, wherein R3 is 2,6-dimethylphen-l-yl or 2-methyl-6-ethylphen-l-yl, R1 is ethyl or methyl, and R2 is methoxy methyl. 16. A process according to Claim 6, wherein the imine corresponds to formula    17. A process according to Claim 1, wherein the iridium catalyst is a homogeneous catalyst that is substantially soluble in the reaction medium.  18. A process according to Claim 1, wherein the catalyst corresponds to formula III, IIIa, IIIb IIIc or IIId.   wherein X is two olefm ligands or a diene ligand, Y is a diphosphine having secondary phosphine groups (a) the phosphine groups of which are bonded to a carbon chain having from 2 to 4 carbon atoms, or (b) the phosphine groups of which are either bonded directly or via a bridge group -CRaRb,- in the ortho positions of a cyclopentadienyl ring or are each bonded to a cyclopentadienyl ring of a ferrocenyl, or (c) one phosphine group of which is bonded to a carbon chain having 2 or 3 carbon atoms and the other phosphine group of which is bonded to an oxygen atom or a nitrogen atom bonded terminally to that carbon chain, or (d) the phosphine groups of which are bonded to the two oxygen atoms or nitrogen atoms bonded terminally to a C2-carbon chain; with the result that in the cases of (a), (b), (c) and (d) a 5-, 6- or 7-membered ring is formed with the Ir atom, the radicals Z are each independently of the other(s) Cl, Br or I, A<-> is the anion of an oxy or complex acid, and M<+> is an alkali metal cation or quaternary ammonium, and Ra and Rb, are each independently of the other hydrogen, C1-C8 alkyl, C1-C4 fluoroalkyl, phenyl or benzyl or are phenyl or benzyl having from one to three C1-C4 alkyl or C1-C4 alkoxy substituents, 19. A process according to Claim 18, wherein the diphosphine Y contains at least one chiral group. 20. A process according to Claim 18, wherein X as an olefin ligand is branched or linear C2-C12 alkylene; and X as a diene ligand is an open-chain or cyclic diene having from 4 to 12 carbon atoms. 21. A process according to Claim 18, wherein the secondary phosphine groups contain two identical or different radicals from the following group: linear or branched C1-C12 alkyl; unsubstituted or C1-C6 alkyl- or C1-C6 alkoxy-substituted C5-C12 cycloalkyl, C5-C12 cycloalkyl-CH2-, phenyl or benzyl; or phenyl or benzyl substituted by halogen (e.g. F, Cl or Br), C1-C6 haloalkyl, (C1-C12 alkyl)3Si, (C6H5)3Si, C1-C6 haloalkoxy (e.g. trifluoromethoxy), -NH2, phenyl2N-, benzyl2N-, morpholinyl, piperidinyl, pyrrolidinyl, (C1-C12 alkyl)2N-, -ammonium-X1<->, -SO3M1, -PO3M1 or by -COO-C1-C6 alkyl (e.g. -COOCH3), wherein M1 is an alkali metal or hydrogen and X1<-> is the anion of a monobasic acid. 22. A process according to Claim 18, wherein the diphosphine Y is of the formula:     wherein R15 and R16 are each independently of the other hydrogen, C1-C4alkyl, phenyl, benzyl, or phenyl or benzyl having from one to three C1-C4alkyl or C1-C4alkoxy substituents, R14 is hydrogen, C1-C4alkyl, phenyl, benzyl, or phenyl or benzyl having from one to three C1-C4alkyl or C1-C4alkoxy substituents, R17 is hydrogen, C1-C4alkyl, phenyl, benzyl, C1-C6 alkoxy-CO-, C1-C6 alkyl-CO-, phenyl-CO-, naphthyl-CO- or C1-C4 alkylNH-CO-, A represents identical or different groups -P(R)2, wherein R is C1-C6 alkyl, cyclohexyl, phenyl, benzyl, or phenyl or benzyl having from one to three C1-C4alkyl, disubstituted ammo, C1-C4alkoxy, -CF3 or partially or fully fluorinated C1-C4alkoxy substituents, and n is 0, 1 or 2. 23. A process according to Claim 18, wherein the secondary phosphine groups of the diphosphines Y are bonded either directly or via a bridge group -CRaRb- in the ortho positions of a cyclopentadienyl ring or are each bonded to a cyclopentadienyl ring of a ferrocenyl. 24. A process according to Claim 23, wherein the diphosphine corresponds to formula X   wherein R14 is hydrogen, C1-C4alkyl, phenyl, benzyl, or phenyl or benzyl substituted by from one to three C1-C4alkyl or C1-C4alkoxy substituents, A represents identical or different groups -P(R)2 wherein R is C1-C 6alkyl, cyclohexyl, phenyl, benzyl, or phenyl or benxyl substituted by from one to three C1-C4alkyl, disubstituted ammo, C1-C4alkoxy, -CF3, or partially or fully fluorinated C1-C4alkoxy substituents. 25. A process according to Claim 24, wherein the diphosphine of formula X is chiral and R14 is C1-C4alkyl, or is phenyl or benzyl substituted by from one to three C1-C4alkyl or C1-C4alkoxy substituents, A represents identical or different groups -P(R)2; wherein R is C1-C6 alkyl, cyclohexyl, phenyl, benzyl, or phenyl or benzyl substituted by from one to three C1-C4alkyl, disubstituted amino, C1-C4alkoxy, -CF3 or partially or fully fluorinated C1-C4alkoxy substituents. 26. A process according to Claim 18, wherein the diphosphine Y is {(R)-l-[(S)-2-diphenylphosphino)ferrocenyl]}ethyl-di(3,5-dimethyl-phenyl)phosphine, {(R)-l-[(S)-2-diphenylphosphino)ferrocenyl]}ethyl-di(3,5-dimethyl-4-N,N-dipropylaminophenyl)phosphine, {(R)-l-[(S)-2-diphenylphosphino)ferrocenyl]}ethyl-di(3,5-diiso-propyl-4-N,N-dimethylaminophenyl)phosphine, {(R)-1-[(S)-2-diph