Enantiopure base-metal catalysts for asymmetric catalysis and bis(imino)pyridine iron alkyl complexes for catalysis
A transition metal-containing compound having a tridentate chiral ligand bound to iron, cobalt, or nickel. The tridentate ligands are bound to the metal via nitrogen, phosphorus, and/or arsenic atoms. The tridentate ligand has a chiral group bound at least one of the nitrogen, phosphorus, and arsenic atoms, and a blocking group may be bound to another one of the nitrogen, phosphorus, and arsenic atoms. The transition metal-containing compound is useful for the catalyzing the asymmetric hydrogenation of olefins.
1. A transition metal-containing compound, represented by formula (I):
or a salt thereof,
wherein
M represents a transition metal atom selected from the group consisting of iron and cobalt;
each of X 1 , X 2 , and X 3 represents a nitrogen atom;
Y 1 represents a chemical bond between X 1 and Z 1 or a carbon-containing group that links X 1 and Z 1 represented by —(CH 2 ) m —, where —, in each occurrence, represents the chemical bond to each of X 1 and Z 1 and m is an integer of 1, 2, 3, 4, 5, or 6;
Y 2 represents a chemical bond between X 2 and Z 2 or a carbon-containing group that links X 2 and Z 2 represented by —(CH 2 ) m —, where—, in each occurrence, represents the chemical bond to each of X 2 and Z 2 and m is an integer of 1, 2, 3, 4, 5, or 6;
each of Z 1 and Z 2 represents a chiral group represented by formula (II) or a blocking group selected from the group consisting of an isopropyl group; a tert-butyl group; a neopentyl group; a cyclopropyl group; a cyclobutyl group; a cyclopentyl group; a cyclohexyl group optionally substituted with at least one methyl group, at least one ethyl group, at least one isopropyl group, at least one tert-butyl group, or a combination thereof; a phenyl group optionally substituted with at least one methyl group, at least one ethyl group, at least one isopropyl group, at least one a tert-butyl group, or a combination thereof; an adamantyl group; a trimethylsilyl group; a triethylsilyl group; a tripropylsilyl group; a tri-iso-propyl silyl group; a tri-tert-butyl group; and a neosilyl group, with the proviso that at least one of Z 1 and Z 2 represents a chiral group represented by formula (II):
wherein each of R 6 and R 7 , individually, represents C 1-20 alkyl group or a C 3-20 cycloalkyl group, with the proviso that R 6 and R 7 do not simultaneously represent the same group, C* represents a nonracemic chiral carbon atom, and C* is bound to the Y 1 or Y 2 group or bound to X 1 or X 2 when Y 1 or Y 2 represents a chemical bond;
n represents an integer of 1;
each R 1 , individually, represents a chemical bond to a carbon atom of Z 1 or Z 2 , a hydrogen atom, a C 1-20 alkyl group, or a halogen atom;
each of R 2 and R 5 , individually, represents a C 1-20 alkyl;
R 3 and R 4 , together, form an aromatic ring having five carbon atoms.
2. The transition metal-containing compound according to claim 1 , wherein M represents an iron atom.
3. The transition metal-containing compound according to claim 1 , wherein M represents a cobalt atom.
4. The transition metal-containing compound according to claim 1 , wherein one of Z 1 and Z 2 represents a chiral group represented by formula (II), R 6 or R 7 represents a tert-butyl group or a cyclohexyl group and the other of R 6 and R 7 represents a methyl group.
5. The transition metal-containing compound according to claim 1 , wherein one of Z 1 and Z 2 represents a chiral group represented by formula (II), R 6 or R 7 represents a tert-butyl group and the other of R 6 and R 7 represents a methyl group.
6. The transition metal-containing compound according to claim 1 , wherein one of Z 1 and Z 2 represents a chiral group represented by formula (II), R 6 or R 7 represents a cyclohexyl group and the other of R 6 and R 7 represents a methyl group.
7. The transition metal-containing compound according to claim 1 , wherein M represents a cobalt atom; one of Z 1 and Z 2 represents a chiral group represented by formula (II); R 6 or R 7 represents a tert-butyl group or a cyclohexyl group; and the other of R 6 and R 7 represents a methyl group.
8. The transition metal-containing compound according to claim 1 , wherein M represents a cobalt atom; one of Z 1 and Z 2 represents a chiral group represented by formula (II); R 6 or R 7 represents a tert-butyl group; and the other of R 6 and R 7 represents a methyl group.
9. The transition metal-containing compound according to claim 1 , wherein M represents a cobalt atom; one of Z 1 and Z 2 represents a chiral group represented by formula (II); R 6 or R 7 represents a cyclohexyl group; and the other of R 6 and R 7 represents a methyl group.
10. The transition metal-containing compound according to claim 1 , wherein
each R 1 , individually, represents a chemical bond to a carbon atom of Z 1 or Z 2 ; a hydrogen atom; a C 1-20 alkyl group selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isobutyl group; or a halogen atom; and
each of R 2 and R 5 , individually, represents a C 1-20 alkyl group selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isobutyl group.
11. The transition metal-containing compound according to claim 1 , which is:
12. The transition metal-containing compound according to claim 1 , which is:
13. The transition metal-containing compound according to claim 1 , which is:
14. The transition metal-containing compound according to claim 1 , which is:
15. The transition metal-containing compound according to claim 1 , which is:
16. The transition metal-containing compound according to claim 1 , which is:
17. The transition metal-containing compound according to claim 1 , which is:
18. The transition metal-containing compound according to claim 1 , which is:
19. The transition metal-containing compound according to claim 1 , which is:
20. The transition metal-containing compound according to claim 1 , which is:
21. The transition metal-containing compound according to claim 1 , which is:
22. The transition metal-containing compound according to claim 1 , which is:
23. The transition metal-containing compound according to claim 1 , which is:
24. The transition metal-containing compound according to claim 1 , which is:
25. A catalyst comprising at least one transition metal-containing compound according to claim 1 .
26. A method, comprising hydrogenating an olefin in the presence of a catalyst according to claim 25 .
27. The transition metal-containing compound according to claim 1 , wherein each of Z 1 and Z 2 represents a chiral group represented by formula (II) or a blocking that is a phenyl group optionally substituted with at least one methyl group, at least one ethyl group, at least one isopropyl group, at least one tent-butyl group, or a combination thereof.
28. A compound selected from the group consisting of
29. The transition metal-containing compound according to claim 1 , wherein each R 1 , individually, represents a chemical bond to a carbon atom of Z 1 or Z 2 , a hydrogen atom, or a C 1-20 alkyl group.
30. The transition metal-containing compound according to claim 1 , wherein each R 1 , individually, represents a chemical bond to a carbon atom of Z 1 or Z 2 or a C 1-20 alkyl group.