Thiahelicene phosphorous derivatives

Tetrathia[7]helicenes (7-TH) are polyconjugated π-systems in which four thiophene rings are ortho-fused to alternating arene rings to generate a non planar and chiral helix, which allows the existence and the separation of the M and P antipodes. Exploiting our well-established know-how in the synthesis and functionalization of 7-TH derivatives, we have recently focused our attention on the study of new 7-TH phosphorous derivatives as potential chiral ligands in asymmetric organometallic catalysis1 and organocatalysis.2 Based on the promising results obtained in these studies, new classes of 7-TH phosphorous derivatives, whose structures are reported in Figure 1, have been synthesized, and their chiroptical, structural, electronic and electrochemical properties have been investigated.