Convenient Access to a N,N'-bis(2,6-terphenyl) Substituted N-Heterocyclic Carbene

The efficient synthesis of a N,N'-bis(2,6-terphenyl) substituted N-heterocyclic carbene (NHC) is reported. The gain in efficiency and total yield, compared to traditional synthesis, is the result of a high yielding and scalable double Suzuki coupling step, affording a 2,6-terphenyl aniline, catalyzed by a Pd beta-diketiminate complex. A stereoelectronic study revealed the new NHC to be very similar to the only other N,N'-bis(2,6-terphenyl) substituted NHC. Application to the stabilization of Group 13 trihydrides gives acceptable outcomes but inferior to those observed when the bulky IPr* NHC is deployed. An efficient synthesis of a sterically demanding 2,6-terphenyl substituted N-heterocyclic carbene is reported. Further studies examined whether this ligand confer thermal stability to Group 13 metal trihydrides. image