SYNTHESIS OF UNSYMMETRICAL BIARYLS VIA KINETIC HIGHER-ORDER CYANOCUPRATES - SCOPE, LIMITATIONS, AND SPECTROSCOPIC INSIGHTS

Treatment of lower order arylcyanocuprates ArCu(CN)Li with 1 equiv of anaryllithium (Ar'Li) at temperatures around -125-degrees-C leads to h igher order reagents Ar(Ar')Cu(CN)Li2. Upon exposure of such reagents at this temperature to ground-state molecular oxygen, good yields of t he unsymmetrical biaryl Ar-Ar' can be realized. Several different type s of aryl ligands have been examined, including naphthalenes, to asses s the generality of this method. Spectroscopic data (C-13 NMR) have be en obtained on three different cuprates at -130-degrees-C and at highe r temperatures to determine if their kinetic nature, as illustrated by their synthetic chemistry, can be substantiated by physical means.