Chiral Helical-Shaped Polyheteroaromatics


Helicenes have attracted interest thanks to their unusual helical-shape and properties: although fully conjugated and aromatic, they are not strictly planar and, moreover, are inherently chiral and generally configurationally stable. These features allow the use of helicenes in such diverse fields as catalysis, material science, optoelectronics, and biology.

Thiahelicenes and beyond

Among helicenes, thiahelicenes are unique thanks to the presence of thiophene rings, which confer special chemical, geometric, and electronic features. In comparison with carbohelicenes, in which no heterocycle is present, they can be easily and regioselectively functionalized. This synthetic flexibility allows the modulation of specific properties, making it easier to exploit their potential applications.                                                                                                              In the past few years we set-up novel synthetic methodologies, involving key intermediates such as atropoisomers, as well as stereoselective pathways to afford thiahelicenes. Moreover we focused on thiahelicenes applications in chiral sensors and as ligand for  organic and organometallic catalysis.

Doping Helicenes with Boron

Recently the introduction of trigonal boron atoms into a polyaromatic core has been recognized as an extremely powerful tool to provide highly conjugated scaffolds with enhanced spectroscopic and electrochemical properties, such as high electron-accepting ability and luminescence quantum yields.    We are trying to combine features of boron π-conjugated systems with those of highly distorted structures, such as helicenes, in a synergistic way, so as to obtain innovative chiral systems with enhanced physico-chemical properties promising for applications in material science.

Peptide Nucleic Acids(PNAs)

Peptide Nucleic Acids (PNAs) are DNA analogues in which the sugar-phosphate backbone has been replaced by N-(2-aminoethyl)glycine units. Despite a radical structural change with respect to DNA and RNA, they are capable of sequence-specific and efficient hybridization with complementary DNA and RNA forming Watson-Crick double helices. In addition, they are able to generate triple helix formation with double-stranded DNA and perform strand invasion.  Accordingly, they have been proposed as very efficient tools for pharmacologically-mediated alteration of gene expression, both in vitro and in vivo.  Our research is aimed at the design and synthesis of PNAs with new structural characteristics, to obtain modified PNAs for diagnostics and as anti‐sense agents.