Pd(0)-Catalyzed Direct C-H Functionalization of 2-H-4-Benzylidene Imidazolones: Friendly and Large-Scale Access to GFP and Kaede Protein Fluorophores
Résumé
The first one‐pot synthesis of N‐substituted 2‐H‐4‐benzylidene imidazolones and their subsequent palladium‐catalyzed and copper‐assisted direct C2−H arylation and alkenylation with aryl‐ and alkenylhalides are described. This innovative synthesis is step‐economical, azide‐free, high yielding, highly flexible in the introduction of a variety of electronically different groups, and can be operated on large‐scale. Moreover, the method allows direct access to C2‐arylated or alkenylated imidazolone‐based green fluorescent protein (GFP) and Kaede protein fluorophores, including ortho‐hydroxylated models.