Recent advances in aza Friedel-Crafts reaction: strategies for achiral and stereoselective synthesis

The aza-Friedel-Crafts (aza-FC) reaction is a very powerful tool for forming C-C and C-N bonds, based on an acid-catalyzed addition of electron-rich aromatic compounds to imines. This reaction has been particularly useful for synthesizing polysubstituted amines bearing various aromatic groups, as this structural motif is present in many biologically active and pharmacologically relevant compounds. Through representative examples, recent improvements achieved on the aza-FC reaction are presented, classified according to the type of catalyst used. Particular emphasis has been put on the different catalysts used to obtain optically active compounds, as the stereoselective addition of a C(sp(2))-H bond to an imine allows access to chiral amines in a completely atom-economical way.