Preparation of bidentate ligands

A process for preparing a bidentate ligand of the formula ##STR12## wherein each Ar is independently selected from aromatic ring compounds having 6 up to 14 carbon atoms;

• the x bonds and the y bonds are attached to adjacent carbon atoms on the ring structures;
• each R, when present as a substituent, is independently selected from alkyl, alkoxy, aryloxy, aryl, aralkyl, alkaryl, alkoxyalkyl, cycloaliphatic, halogen, alkanoyl, alkanoyloxy, alkoxycarbonyl, carboxyl, cyano or formyl radicals;
• n is a whole number in the range of 0-4 where Ar is phenyl;
• 0-6 where Ar is naphthyl;
• and 0-8 where Ar is phenanthryl or anthracenyl;
• each R.sub.1 and R.sub.2 is independently selected from alkyl, aryl, aralkyl, alkaryl or cycloaliphatic radicals or substituted derivatives thereof;
• wherein substituted derivatives thereof are selected from alkoxy, aryloxy, alkoxyalkyl, halogen, alkanoyl, alkanoyloxy, alkoxycarbonyl, cyano, carboxyl or formyl substituted compounds;
• each R.sub.3 is independently selected from hydrogen and the R.sub.1 substituents;
• each of the above alkyl groups or moieties is a straight or branched chain of 1-20 carbons;
• preferably 1-8 carbons;
• each aryl group contains 6-10 ring carbons;
• each cycloaliphatic group contains from 4-8 ring carbons;
• and
• each Y is independently selected from the elements N, P, As, Sb and Bi;
• said process comprising the steps,
• (1) contacting with ozone under ozonolysis conditions a suspension in a hydroxylic reaction medium of a reactant selected from phenanthrene or a phenanthrene derivative having the structure:
• ##STR13## wherein each Z 4 through 12 carbon fragment completing a single aromatic ring or a fused ring system, respectively, to form an ozonated intermediate;
• (2) contacting said ozonated intermediate with a reducing agent under conditions appropriate to form a diol having the structure:
• ##STR14## (3) contacting with diol with an activating agent comprising a latent displaceable functional group, X, under conditions sufficient to convert the diol to a difunctional biaryl compound having the structure:
• ##STR15## wherein X is a functional group which can be displaced under nucleophilic substitution conditions,
• (4) contacting said difunctional biaryl compound with an anion having the structure:
• ##STR16## wherein Y' is selected from the group consisting of P, As, Sb and Bi;
• in a molar ratio of anion to difunctional biaryl compound in the range of about 1/1 up to 20/1 under conditions appropriate to displace X and thereby form the above bidentate ligand or an oxygenated intermediate product thereof;
• and
• (5) optionally reducing the oxygenated intermediate product when the oxy-anion, ##STR17## is employed as the anion in step (4).