Catalyst system containing Ni(0) for hydrocyanation
A system comprising a) Ni(0) b) from 4 to 10 mol per mol of Ni(0) in a) of a compound (I) of the formula P(X 1 R 1 )(X 2 R 2 )(X 3 R 3 ) (I) where X 1 , X 2 , X 3 are each, independently of one another, oxygen or a single bond, R 1 , R 2 , R 3 are, independently of one another, identical or different organic radicals and c) from 1 to 4 mol per mol of Ni(0) in a) of a compound (II) of the formula where X 11 , X 12 , X 13 X 21 , X 22 , X 23 are each, independently of one another, oxygen or a single bond, R 11 , R 12 are identical or different, individual or bridged organic radicals, R 21 , R 22 are identical or different, individual or bridged organic radicals and Y is a bridging group is suitable as catalyst for preparing mixtures of monoolefinic C 5 mononitriles having nonconjugated C═C and C═N bonds by hydrocyanation of a 1,3-butadiene-containing hydrocarbon mixture and for preparing a dinitrile by hydrocyanation of a mixture of monoolefinic C 5 mononitriles having nonconjugated C═C and C═N bonds.
1. A system comprising
a) Ni(0)
b) from 4 to 10 mol per mol of Ni(0) in a) of a compound (I) of the formula
( o -Tolyl-O) w ( m -Tolyl-O) x ( p -Tolyl-O—) y (Phenyl-O—) z P
where
w, x, y, z are each a natural number and
w+x+y+z=3 and
w, z are each less than or equal to 2,
and
c) from 1 to 4 mol per mol of Ni(0) in a) of a compound (II) of the formula
where
X 11 , X 12 , X 13 , X 21 , X 22 , X 23 are each oxygen,
R 11 , R 12 are identical or different, phenyl radicals which are unsubstituted or mono- or polysubstituted by C 1 -C 4 -alkyl,
R 21 , R 22 are identical or different, phenyl radicals which are unsubstituted or mono- or polysubstituted by C 1 -C 4 -alkyl, and
Y is a substituted or unsubstituted pyrocatechol, bis(phenol) or bis(naphthol) group,
which is suitable as a catalyst.
2. A system as claimed in claim 1 , wherein the number of phenyl groups in compound (I) is not more than 2 and the number of o-tolyl groups in compound (I) is not more than 2.
3. A system as claimed in claim 1 , comprising an Ni(0) complex of the formula
Ni(0)(compound (I)) x (compound (II))
where x=1, 2.
4. A process for preparing a system as defined in claim 1 , which comprises
a) reacting Ni(0) with a compound (I) in the presence of a liquid diluent to give a first system comprising Ni(0) and the compound (I) and then
b) reacting this first system with a compound (II) in the presence of a liquid diluent to give the system as claimed in claim 1 .
5. A process as claimed in claim 4 , wherein metallic nickel is used as Ni(0) in step a).
6. A process as claimed in claim 4 , wherein from 4 to 10 mol of compound (I) are used per mol Ni(0) in step a).
7. A process as claimed in claim 4 , wherein the liquid diluent used in step a) is a compound of the formula (I), 3-pentenenitrile, 4-pentenenitrile, 2-methyl-3-butenenitrile, adiponitrile, methylglutaronitrile, an aromatic, an aliphatic or a mixture thereof.
8. A process as claimed in claim 4 , wherein the preparation of the first system in step a) is carried out in the presence of a catalyst.
9. A process as claimed in claim 4 , wherein the preparation of the first system in step a) is carried out in the presence of a homogeneous catalyst.
10. A process as claimed in claim 4 , wherein the preparation of the first system in step a) is carried out in the presence of a protic acid as homogeneous catalyst.
11. A process as claimed in claim 4 , wherein the preparation of the first system in step a) is carried out in the presence of hydrogen chloride as homogeneous catalyst.
12. A process as claimed in claim 4 , wherein the preparation of the first system in step a) is carried out in the presence of a compound of the formula (R 1 X 1 )(R 2 X 2 )PCl or (R 1 X 1 )PCl 2 , where
X 1 , X 2 are each oxygen, and
R 1 , R 2 are each, independently of one another, a phenyl, o-tolyl, m-tolyl or p-tolyl group,
as homogeneous catalyst.
13. A process as claimed in claim 4 , wherein the catalyst is removed between step a) and step b).
14. A process as claimed in claim 4 , wherein from 1 to 4 mol of compound (II) are used per mol Ni(0) in step b).
15. A process as claimed in claim 4 , wherein the liquid diluent used in step b) is a compound of the formula (I), 3-pentenenitrile, 4-pentenenitrile, 2-methyl-3-butenenitrile, adiponitrile, methylglutaronitrile, an aromatic, an aliphatic or a mixture thereof.
16. A process as claimed in claim 4 , wherein the same liquid diluent is used in step a) and in step b).