Hydrocyanation process and multidentate phosphite and nickel catalyst composition therefor

A hydrocyanation process comprising reacting an acyclic, aliphatic, monoethylenically unsaturated compound in which the ethylenic double bond is not conjugated to any other olefinic group in the molecule, or a monoethylenically unsaturated compound in which the ethylenic double bond is conjugated to an organic ester group, with a source of HCN in the presence of a catalyst composition comprising a Lewis acid, a zero-valent nickel, and at least one multidentate phosphite ligand selected from the group represented by the following Formulas I, II, III, IV, V, VI and VII:

• ##STR34## wherein each R.sup.1 is independently, H, halogen, a C.sub.1 to C.sub.6 alkyl, or OR.sup.3 wherein R.sup.3 is a C.sub.1 to C.sub.6 alkyl;
• each R.sup.2 is independently a secondary or tertiary hydrocarbyl of 3 to 6 carbon atoms;
• each R.sup.2' is independently H, halogen, OR.sup.3 wherein R.sup.3 is a C.sub.1 to C.sub.6 alkyl or a primary, secondary or tertiary hydrocarbyl of 1 to 6 carbon atoms;
• for Formulas II, III, IV, VI and VII, R.sup.2' is at either the meta or para position to the oxygen;
• each R.sup.5' is independently H or a primary or secondary hydrocarbyl of 1 to 3 carbon atoms in either the ortho or meta position to the oxygen or CO.sub.2 R.sup.3' where R.sup.3' is a C.sub.1 to C.sub.4 alkyl;
• and
• each X is independently O or CH(R.sup.4'), wherein R.sup.4' is H, a substituted phenyl, or a C.sub.1 to C.sub.6 alkyl;
• with the proviso that the terms "secondary" and "tertiary" herein refer to the carbon atom bonded to an aromatic ring;
• and with the further proviso that in Formulas I, II, and V at least one R.sup.2 cannot be a tertiary hydrocarbyl.