We report here that the undesired hydrodehalogenation in cross-coupling reactions with fluorinated substrates involves water as a possible hydrogen source. Moreover, the product distribution (hydrodehalogenation vs carbon-carbon coupling) can be controlled by varying the phosphine substituents. Significant hydrodehalogenation occurs prior to the formation of Ar F-Pd(II)-Br complexes. DFT calculations were used to evaluate a direct hydrodehalogenation route with a phosphine and water. These findings provide new mechanistic insight into aryl-Br bond activation with fluorinated substrates and selective arene functionalization.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry