Interactions in solution based on sigma-hole: towards the design of a whole new family of organocatalysts with halogen/chalcogen bonds as key interaction

During this last decade, halogen and chalcogen bonds (XB and ChalB) have increasingly raised interest in the scientific community. According to IUPAC, the term halogen bond describes the intermolecular interaction occurring between a halogen acting as a Lewis acid and a Lewis base[1]. XB represents one of the so-called ?-hole interactions (?hI)[2] with relevance evidence in biology, recognition processes and in crystal engineering[3]. So far studied in vacuum and in solid state, such interactions have been less investigated in solution. However, they could be useful in chiral recognition, in separation[4] and in organocatalysis. To look at this aspect, we designed atropisomeric 4,4'-bipyridyl[5],[6] with exalted ?-holes (Figure 1.). After identifying the best ?hI donors and studying them through chiral environment [7],[8] we are investigating them as organocatalyst.