Cu(II)-Catalyzed Construction of Heterobiaryls using 1-Diazonaphthoquinones: A General Strategy for the Synthesis of QUINOX and Related P,N Ligands.

An efficient and straightforward method was developed for the synthesis of heterobiaryls using easily available N -oxides and diazonaphthoquinones under cheap Cu(II) catalysis. The developed method offered QUINOX and related congeners in a simple manner. A wide scope of important heterobiaryls was achieved with high site selectivity. The synthesized naphthols were transformed into the privileged related P,N ligands. Suitable resolution methods can directly afford the corresponding axially chiral heterobiaryls.