From reactive carbenes to chiral polyether macrocycles in two steps - synthesis and applications made easy?

Chiral polyether macrocycles are versatile molecules. For their preparation, original two-step procedures were recently developed and present the advantages of high concentration conditions and simple starting reagents (stable diazo reagents, small cyclic ethers, aliphatic or aromatic amines). Enantiopure materials are readily afforded by CSP-HPLC on a semi-preparative scale.

Merging polyacenes and cationic helicenes: from weak to intense chiroptical properties in the far red region.

A series of helical tetracenes and pentacenes was synthesized from cationic [6] and [4]helicene precursors. These colorful acenes fluoresce in the far red region. While [4]helicene-based pentacenes exhibit chiroptical properties mainly in the UV region, [6]helicene-derived tetracenes show enhanced ECD in the visible range, in addition to clear CPL responses.