Grafting Bis(heteroaryl) Motifs into Ring Structures

Here we demonstrate an approach to graft bis(heteroaryl)-containing motifs into ring structures. The process occurs by redirecting a previously reported oxadiazole-forming reaction towards a pyrazole-forming process affording pyrazolyl-azole containing molecules. Through the use of (N-isocyanimino)phosphorane (Pinc), heteroatom-rich fused tricyclic heterocycles can be synthesized in a single step from readily accessible starting materials. The cyclization of peptides results in macrocycles that feature bis(heteroaryl) motifs with uncommon connectivity as compared to their natural counterparts.