Preparation of bidentate ligands

A process for preparing a bidentate ligand of the formula:

• ##STR15## 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, aryloxy alkyl, cycloaliphatic, halogen, alkanoyl, aroyl, alkanoyloxy, aroyloxy, alkoxycarbonyl, aryloxy carbonyl, carboxyl, sulfonic acid, 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 include ethers, amines, amides, sulfonic acids, esters, hydroxyl groups and alkoxy groups;
• each R.sub.3 and R.sub.4 is independently selected from hydrogen and the R.sub.1 substituents;
• each of the above alkyl groups or moieties is straight or branched chain of 1-20 carbons;
• each aryl group or moiety contains 6-10 ring carbons;
• each cycloaliphatic group contains from 4-8 ring carbons;
• and
• each Y is independently selected from the elements P, As, Sb and Bi;
• said process comprising:
• (1) contacting a biaryl compound having the structure:
• ##STR16## with a proton abstracting agent under conditions suitable to form a biaryl dianion, which is then
• (2) contacted with a Group V compound of the formula:
• ##STR17## where X' is halogen or a suitable leaving group.