Exploring Trifluoromethylation Reactions at Nickel: A Structural and Reactivity Study

Abstract

A variety of nickel(aryl)(CF 3 ) complexes supported by a chelating bisphosphine were successfully prepared in order to investigate the possibility of reductive elimination of Ar-CF 3 . The first structural comparison of a Ni-CF 3 complex with a Ni-CH 3 complex is also presented. All of the new nickel(aryl)(CF 3 ) complexes were thermally stable and did not produce Ar-CF 3 under thermal conditions. Additives had very little effect on the reductive eliminations, although water was found to afford product in 22% yield.

Exploring Mechanisms in Ni Terpyridine Catalyzed C–C Cross-Coupling Reactions—A Review

“…Since [Ni(tpy)Br2] is reduced at the lowest potential (−1.30 V), compared with the other metal complexes studied in this work (e.g., (−1.12 V for [Ni(bpy)Br2]), the yields of the cross-coupling product with [Ni(tpy)Br2] participation are relatively higher (up to 73%) [72]. [95,96]. Instead, the Ni(II) σ-complexes 29 transmetalate copper halide species to yield [Cu(II)(L)(R F )(aryl)] 32.…”

Reductive Elimination of ArCF3 from Bidentate PdII Complexes: A Computational Study

“…We used the cis complexes as a starting point, as studies suggested these to be the predominant species in solution. [5,7,8] We applied a QM/QM' computational approach [11] with the layer partitioning A or B, or full geometry optimizations of the complexes. Figure 1 illustrates the…”

“…[6] Similarly, Ni II complexes also gave only poor conversions to ArCF 3 when 1,2-bis(diisopropylphosphino)ethane (DIPPE) bidentate ligands were employed. [8] Reductive eliminations from similar complexes bearing a CH 3 group instead of CF 3 , in contrast, are facile. [7,9] We applied computational studies [10] to explore the origins of these observations, particularly to understand the remarkable effect of Xantphos in the reductive elimination of [Pd…”

Decarboxylative trifluoromethylation of aryl halides using well-defined copper–trifluoroacetate and –chlorodifluoroacetate precursors

“…The catalytic trifluoromethylation of non-activated organic halides represents a long-standing goal in organometallic chemistry [1][2][3][4][5][6][7][8][9][10]. The ability to introduce a trifluoromethyl group into a molecule of interest at a late stage of a synthesis using mild conditions alleviates the need to carry the fluorine functional group through potentially incompatible synthetic procedures, thereby eliminating potential side-reactions and raising overall yields.…”

“…Motivated by the intense commercial and scientific interest in trifluoromethylation reactions, several key studies have highlighted some of the problematic steps of catalysis [1][2][3][4]17]. Perhaps most well-documented is the difficulty in reductive elimination of Ar-CF 3 from low valent Group 10 metal centers, which poses a serious challenge to the development of new catalysts for the trifluoromethylation of aryl bromides and chlorides [1,4,17].…”