Alkylation of azoles with alkenes catalyzed by the NiCl2Py2/IMes • HCl/ButONa system

A new approach to the alkylation of azoles with alkenes catalyzed by the nickel complexes with N-heterocyclic carbenes (Ni/NHC) was developed. The catalytically active Ni/NHC complexes are formed in situ from the air-stable precursors: the nickel chloride complex with pyridine (NiCl₂Py₂), imidazolium salt IMes•HCl (IMes is 1,3-bis(2,4,6-trimethylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene) as the carbene source, and sodium tert-butoxide (Bu^tONa). The advantages of the developed approach are availability of the components of the catalytic system, no necessity to apply special agents for the reduction of Ni^II to Ni⁰, and simplification of the synthesis procedure.