Benzimidazolinylidene-Amide and -Imine Ligands: Donor Strength Determination and Catalytic Studies

Electronically flexible ligands are an emerging class of ligands that possess the unique ability to adapt their donor strength based on the electronic demands of their coordinating environment. Here, the preparation of benzimidazolinylidene-imines (BYIs) and -amides (BYAs) as well as their first palladium(II) complexes is described. The latter could represent a new class of electronically flexible ligands. The electronic properties of these BYI and BYA ligands were evaluated using the Huynh electronic parameter (HEP). The preliminary catalytic application of bis(BYI) and bis(BYA) palladium(II) complexes in the direct C-H arylation of heteroarenes was also explored.