A Heterogeneous-Catalyst-Based, Microwave-Assisted Protocol for the Synthesis of 2,2’-Bipyridines

A new method of preparing 2,2’-bipyridines with short reaction times by using microwave assistance and heterogeneous catalysts has been developed. With a Negishi-like protocol, it was found that Ni/Al2O3–SiO2 afforded 2,2’-bipyridine products in up to 86 % yield in 1 h. Palladium supported on alumina also provided yields of 2,2’-bipyridines comparable to those seen for homogeneous PEPPSITM (1,3-diisopropylimidazol-2-ylidene)(3-chloropyridyl)palladium(II)dichloride)    and tetrakis(triphenylphosphanyl)palladium complexes.