A Straightforward Route to Helically Chiral N‐Heteroaromatic Compounds: Practical Synthesis of Racemic 1,14‐Diaza[5]helicene and Optically Pure 1‐ and 2‐Aza[6]helicenes

Abstract

The taming of the screw: The CoI-catalyzed cyclotrimerization of triynes and microwave (MW) assisted aromatization with MnO2 are central to the practical synthesis of diaza[5]helicene and aza[6]helicenes. The aza[6]helicene racemates have been resolved, the absolute configuration of the enantiomers assigned, the energy barriers to racemization determined, and X-ray structures of their Ag complexes obtained (see picture; Cp=C5H5, OTf=triflate).