Catalysis of Free C–C Bond Rotation: C–F---H–X H-Bonds Find a Catalytic Role

There are few dynamic processes in organic chemistry that are more central to the molecular structure than C–C bond rotation. It is notable, however, that there exist few (if any) cases in which its hindered variants can actually be catalyzed. In this communication, we report a unique model system for the clear documentation of the catalysis of 360° C–C bond rotation that employs a transient but key N–H---F–C hydrogen bond as a linchpin and secondary “dual” charge-induced n → π* interactions and ion pairing effects that bolster catalysis.