Rhodium(III)-catalyzed C-H Activation for the Synthesis of N-containing Heterocyclic Compound

An efficient method for the synthesis of highly popular N- containing heterocyclic compound from imidazolium substrate and alkyne is described. Treatment of diphenylacetylene with diimidazolium in the presence of Cp^*RhCl₂₂ (0.005 mmol, mole fraction is 5%), NaOAc (0.16 mmol), AgOTf(1.2 mmol) as oxidizing agent catalyzing dibromo imidazole salt 1 (0.1 mmol) and diphenylacetylene 2 (0.5 mmol) led to compound 3 in 80% yield. The object molecule was characterized by NMR spectroscopy (¹H, ¹³C, COSY, HSQC and HMBC) and single-crystal structure. Resultsshowthat the crystallographic data forcompound3:space group:P2₁/n, a=16.68(5) Å, b=8.66(3) Å, c=18.48(6) Å, b=93.71(5)°, V=2 664(14) ų, Z=2, Dc=1.350×10³ kg/m³, F(000) 112 4, R₁=0.086 7, wR₂=0.227 5。