Synthesis of Symmetrical Biaryls by Copper-Catalysed Homocoupling of Aryltriazenes in Guanidinium Ionic Liquid

An efficient, facile and practical protocol to synthesize various biaryl analogues by the homocoupling of aryl triazenes promoted by guanidinium ionic liquids via copper catalysis has been demonstrated. The three different guanidinium ILs has been employed as solvent/promoter. Several moderate to strong electron-withdrawing groups and electron-donating groups are well tolerated by this protocol. The predictive mechanism demonstrating the Cu-catalytic cycle and role of GIL as promoter. This methodology provides the corresponding products in good yields under moderate reaction conditions with potential for recycling and reuse of the GIL solvent. Guanidinium ionic liquid has been employed as promoter and reusable solvent to synthesise symmetrical biaryls by homocoupling of aryltriazenes. Presenting protocol, catalysed by copper acetate with aid of base was demonstrated for various aryltriazenes to excess symmetrical biaryls.image