C-H Bond Activation of Palladium Complexes That Feature Pendant Benzamidinate Ligands and Their Catalytic Behaviours

Abstract

The pendant benzamidines {Ph-C[= N-(2,6-di-iPr-C6H3)](NH boolean AND E)} [boolean AND E = (CH2)(2)NMe2, CH2Py] and their palladium complexes [(Ph-C{=N boolean AND E}{NH-(2,6-di-iPr-C6H3)})Pd(OAc)(2)] [boolean AND E = (CH2)(2)NMe2 (1), CH2Py (2)] have been prepared. Upon heating, the corresponding palladacyclic complexes, [({eta(1)-C6H4}-C(=N boolean AND E){NH-(2,6-di-iPr-C6H3)})PdOAc] [boolean AND E = (CH2)(2)-NMe2 (3), CH2Py (4)], were obtained. Due to the substituent groups on the ortho positions of the phenyl ring attached to the nitrogen atom of the amidinate group, the C-H bond activation process was observed on the ortho position of the phenyl ring attached to the carbon atom of the amidinate group. This process can be proved by X-ray structural determination. The molecular structures are reported for compounds 1 and 4. Catalytic application of cyclopalladated derivatives 3 and 4 toward the Suzuki reaction was also investigated.