(Amino)(Aryl)Carbenes: Stable Singlet Carbenes Featuring a Spectator Substituent

Several (amino)(aryl)carbenes have been shown to be stable at room temperature in solution and in the solid state. Electroneutrality of the carbene center is ensured by the amino group, which has both pi-donor and final sigma-acceptor electronic character. The aryl group remains a spectator substituent, as shown by single-crystal x-ray analysis and by its chemical behavior. Because only one electron-active substituent is needed, numerous stable carbenes will become accessible, which will open the way for new synthetic developments and applications in various fields.