反应详情

The coupling reaction was carried out in toluene using Pd2(dba)3 as the catalyst precursor and the desired aniline at 90° C. overnight. After the reaction was completed the solution turned dark with an intense yellow coloration. Both compounds were isolated as yellow solids. 2-Ph-H was synthesized in good yield (76%), but when 2,6-diisopropylaniline was used to produce 2-Dipp-H, the yield decreased considerably (46%). Even over increased periods of time, no significant change in the yield was observed. This result is most likely a consequence of the steric hindrance afforded by the bulky 2,6-diisopropyl groups, diminishing the coordination of the amine to the palladium center. Neither 2-Ph-H nor 2-Dipp-H displayed fluorescence upon irradiation with UV light (254 nm). For 2-Dipp-H the 1H NMR displayed the characteristic resonance for the 2,6-diisopropyl groups and both ligands showed the amine proton shifted down field. The aromatic region of the 1H NMR spectrum was complicated by the overlap of some signals; nevertheless it was fully assigned using 2D experiments.

1. customThe coupling reaction
2. customat 90° C.
3. customovernight
4. customBoth compounds were isolated as yellow solids
5. custom2-Ph-H was synthesized