Enantioselective Synthesis of Biaryl Compounds via Suzuki-Miyaura Cross-Coupling Using a Palladium Complex of 7′-Butoxy-7-(diphenylphosphino)-8,8′-biquinolyl: Investigation of a New Chiral Ligand Architecture

7,7'-Dihydroxy-8,8'-biquinolyl was converted to the title phosphine in four-steps via Mitsunobu monoetherification, trifylation, phosphination, and phosphine oxide reduction (63% overall yield). Enantiomerically pure phosphine was combined with Pd(2)dba(3) and investigated for the synthesis of axially chiral biaryl compounds from (ArBr)-Br-1 and (ArB)-B-2(OH)(2) in the presence of K3PO4 in toluene solvent (6 examples, 4-97% yield, 4-74% ee). The analogous carbocyclic ligand 2-(diphenylphosphino)-2'-methoxy-1,1'-binaphthyl (MOP) was studied for comparative purposes and found to be effective for the synthesis of hindered 2,2'-disubstituted 1,1'-binaphthyls (78-83% yield, 20-38% ee).