Process for the preparation of nickel/phosphorous ligand catalyst for olefin hydrocyanation
A process for preparing a hydrocyanation catalyst comprising contacting a bidentate phosphorous-containing ligand with nickel chloride in the presence of a nitrile solvent and a reducing metal which is more electropositive than nickel the nickel chloride being introduced as an aqueous solution and the water being removed concurrently with the reduction reaction by azeotropic distillation.
1. A process for preparing a hydrocyanation catalyst comprising contacting at least one bidentate phosphorus-containing ligand selected from the group consisting of bidentate phosphites and bidentate phoshinites, with nickel chloride, in the presence of a nitrile solvent, and a reducing metal that is more electropositive than nickel, wherein the nickel chloride is introduced as an aqueous solution wherein (i) the water is removed concurrently with the reduction of the nickel chloride by azeotropic distillation or (ii) the water is removed by azeotropic distillation, followed by reduction of the NiCl 2 .
2. The process of claim 1 wherein the bidentate phosphorus-containing ligand is a bidentate phosphite.
3. The process of claim 2 wherein the reducing metal is selected from the group consisting of Na, Li, K, Mg, Ca, Ba, Sr, Ti, V, Fe, Co, Cu, Zn, Cd, Al, Ga, In, and Sn.
4. The process of claim 3 further comprising separating unreacted nickel chloride or reducing metal from the hydrocyanation catalyst.
5. The process of claim 3 wherein the reducing metal is Zn or Fe.
6. The process of claim 2 wherein the catalyst preparation is conducted at a temperature of 0° C. to 80° C. and at a pressure of about 0.07 kPa to about 20 kPa.
7. The process of claim 6 wherein the catalyst preparation is conducted at a temperature of about 20° C. to about 60° C.
8. The process of claim 2 wherein the molar ratio of NiCl 2 to the reducing metal is 0.1:1 to 100:1.
9. The process of claim 8 wherein the molar ratio of NiCl 2 to the reducing metal is 0.5:1 to 2:1.
10. The process of claim 9 wherein the bidentate phosphorous-containing ligand is a compound having the formula
(R 1 O) 2 P(OZO)P(OR 1 ) 2 ,
wherein R 1 is phenyl, unsubstituted or substituted with one or more C 1 to C 12 alkyl or C 1 to C 12 alkoxy groups; or naphthyl, unsubstituted or substituted with one or more C 1 to C 12 alkyl or C 1 to C 12 alkoxy groups; and Z and Z 1 are independently selected from the group consisting of structural formulae IV, V, VI, VII, and VIII:
and wherein
R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 are independently selected from the group consisting of H, C 1 to C 12 alkyl, and C 1 to C 12 alkoxy;
X is O, S, or CH(R 10 );
R 10 is H or C 1 to C 12 alkyl;
and wherein
R 11 and R 12 are independently selected from the group consisting of H, C 1 to C 12 alkyl, and C 1 to C 12 alkoxy; and CO 2 R 13 ,
R 13 is C 1 to C 12 alkyl or C 6 to C 10 aryl, unsubstituted or substituted, with C 1 to C 4 alkyl;
Y is O, S, or CH(R 14 );
R 14 is H or C 1 to C 12 alkyl;
wherein R 15 is selected from the group consisting of H, C 1 to C 12 alkyl, and C 1 to C 12 alkoxy and CO 2 R 16 ;
R 16 is C 1 to C 12 alkyl or C 6 to C 10 aryl, unsubstituted or substituted with C 1 to C 4 alkyl,
wherein the structural formulae I through VIII, the C 1 to C 12 alkyl, and C 1 to C 12 alkoxy groups are straight chain or branched.
11. The process of claim 2 wherein said process further comprises contacting the catalyst with 3-pentenenitrile and hydrogen cyanide to produce adiponitrile.