Efficient Catalytic Activity of Copper/Aluminum Hydrotalcite in Diaryl Ether Synthesis

Unexpected C–N bond formation via Smiles rearrangement: one pot synthesis of N-arylated coumarin/pyran derivatives

A conceptually new and one-pot method for the synthesis of N-arylated coumarin/pyran derivatives via Smiles rearrangement.

Recyclable heterogeneous copper oxide on alumina catalyzed coupling of phenols and alcohols with aryl halides under ligand-free conditions

An efficient alumina-supported CuO-catalyzed O-arylation of phenols and aliphatic alcohols with various aryl as well as heteroaryl halides under ligand-free conditions are reported. This protocol provides a variety of diaryl ether and bis-diaryl ether motifs by reacting different aryl/aliphatic halides with differently substituted phenols and saturated alcohols in the presence of a catalytic amount of CuO on alumina and KOH as a base at moderate temperature under nitrogen atmosphere. The described methodology is simple, straightforward and efficient to afford the cross-coupled products in high yields under ligand-free conditions. The explored catalyst is inexpensive, air-stable and recyclable up to three cycles.