Use of a multidentate phosphite ligand in the catalytic synthesis of adiponitrile

A method of catalytic synthesis of adiponitrile using a multidentate phosphite ligand, wherein the multidentate phosphite ligand is a compound represented by a following general formula (I), the method comprising:

• subjecting butadiene and hydrocyanic acid to a primary hydrocyanation reaction in the presence of a first catalyst;
• subjecting a branched mononitrile mixture to an isomerization reaction of branched mononitriles in a presence of a second catalyst, wherein the branched mononitrile mixture is separated from a product obtained in the primary hydrocyanation reaction;
• and
• subjecting a linear mononitrile mixture and hydrocyanic acid to a secondary hydrocyanation reaction in the presence of a third catalyst and a promoter to obtain a product containing adiponitrile, wherein the linear mononitrile mixture is separated from the products obtained in the primary hydrocyanation reaction and the isomerization reaction;
• wherein the first catalyst, the second catalyst, and the third catalyst are identical or different, and each of the catalysts comprises a phosphite ligand-zero-valent nickel complex formed of a nickel precursor and the multidentate phosphite ligand:
• in formula (1), R0 is —O-A4, H, an C1˜6 alkyl group, a substituted or unsubstituted C3˜10 cycloalkyl group, or a substituted or unsubstituted C6˜20 aryl group;
• R11 to R16 are identical to or different from each other, and each independently represents hydrogen, an C1˜6 alkyl group, a substituted or unsubstituted C3˜10 cycloalkyl group, or a substituted or unsubstituted C6˜20 aryl group;
• A1, A2, A3, and A4 are identical to or different from each other, and each independently is
• each of R21 and each of R22 are identical to or different from each other, and each of R21 and each of R22 is independently H, a substituted or unsubstituted C1˜6 alkyl group, a substituted or unsubstituted C3˜10 cycloalkyl group, a C1˜6 acyl group, or a substituted or unsubstituted C6˜20 aryl group;
• and
• R21 and R22 may bond to form a ring via a single bond, an C1˜6 alkylene group, a phenylene group, or a C1˜6 alkyl substituted phenylene group;
• Q is a single bond, an C1˜3 alkylene group, an oxygen atom, a nitrogen atom, or an C1˜3 alkylene group containing an oxygen atom or a nitrogen atom.