1215465-52-3Relevant articles and documents
Mechanistic and computational studies of oxidatively-induced Aryl-CF 3 bond-formation at Pd: Rational design of room temperature aryl trifluoromethylation
Ball, Nicholas D.,Gary, J. Brannon,Ye, Yingda,Sanford, Melanie S.
, p. 7577 - 7584 (2011/06/25)
This article describes the rational design of first generation systems for oxidatively induced Aryl-CF3 bond-forming reductive elimination from PdII. Treatment of (dtbpy)PdII(Aryl)(CF3) (dtbpy = di-tert-butylbipyridine) with NFTPT (N-fluoro-1,3,5-trimethylpyridinium triflate) afforded the isolable PdIV intermediate (dtbpy)Pd IV(Aryl)(CF3)(F)(OTf). Thermolysis of this complex at 80 °C resulted in Aryl-CF3 bond-formation. Detailed experimental and computational mechanistic studies have been conducted to gain insights into the key reductive elimination step. Reductive elimination from this PdIV species proceeds via pre-equilibrium dissociation of TfO- followed by Aryl-CF3 coupling. DFT calculations reveal that the transition state for Aryl-CF3 bond formation involves the CF3 acting as an electrophile with the Aryl ligand serving as a nucleophilic coupling partner. These mechanistic considerations along with DFT calculations have facilitated the design of a second generation system utilizing the tmeda (N,N,N′,N′-tetramethylethylenediamine) ligand in place of dtbpy. The tmeda complexes undergo oxidative trifluoromethylation at room temperature.
