Transition metal-mediated synthesis of monocyclic aromatic heterocycles

The article presents transition metal-mediated synthesis of monocyclic aromatic heterocycles. The development of selective and general methods for a facile assembly of the diversely substituted furan core attracted tremendous interest over the past few decades. Consequently, numerous reviews covering a large number of existing synthetic methods toward furans via a modification of preexisting heterocyclic core and assembly of the ring from acyclic precursors have appeared. Gevorgyan and co-workers demonstrated that easily available conjugated alkynyl ketones could indeed serve as highly versatile surrogates of somewhat unstable and not so simply accessible allenones, which are typically used in many efficient furan syntheses. Bearing in mind the development of milder and safer conditions for cycloaddition of nitriles and azides, Bosch and Vilarrasa developed the Cu(I)-catalyzed synthesis of 1,5-disubstituted tetrazoles.