Stable Fluorophosphines: Predicted and Realized Ligands for Catalysis

Abstract

Ligand maps lead to treasure! The activity of complexes of fluorophosphines (R2PF) in catalytic hydroformylation and hydrocyanation is predicted from a ligand map. However, the instability of R2PF to disproportionation is well‐documented. Examples of R2PF ligands (see scheme) are described that are stabilized to such an extent that they can be used in catalysis and are shown to be highly effective.

Carbeniophosphines versus Phosphoniocarbenes: The Role of the Positive Charge

“…Overall, based on both electronic parameter's scales derived from two complementary families of Rh I -carbonyl complexes, imidazoliophosphines, and more generally carbeniophosphines, have to be considered as actual alternatives to the neutral electron-poor fluorophosphines [45] and phosphi(ni)tes. [46] Although the objective of lowering the donating character of the phosphine ligands by incorporating ap roximal positive chargeh as been achieved, carbeniophosphines retain sufficient coordinating ability towards various Lewis acid centers of metallic( Rh I , [6,47] Pd II , [6,48] Ni II , [49] Cu I , [50] Ag I , [51] Au I , [6,16] etc.)…”

“…Beyondt he intrinsic reactivity of a-cationic phosphines, the presence of ap ositivec harge in the vicinity of the coordinating Pc enteri se xpectedt of avor catalytic processes requiring electron-poor metal complexes. Carbeniophosphines were thus considered as valuable alternatives to the more widely used fluorophosphine [45] or phosphite ligands. [46] In the a-cationic series, imidazoliophosphines were evaluated in homoge-Scheme7.The synthesis of persistent radicals stabilized by Caac carbenes, P-centered radical 23, [55] or C-centered radicals 24 a-c and their related Au I complexes 25 a, b.…”

A straightforward access to ruthenium-coordinated fluorophosphines from phosphorous oxyacids

“…5 Up to now very few applications of fluorophosphines in catalysis have been described, owing to their instability with respect to the redox disproportionation. 6 It is known indeed that difluorophosphines RPF 2 decompose giving RPF 4 and RP. Recently, Pringle and his group have prepared remarkably stable fluorophosphines based on both phospha-adamantane cages and phosphabicycles, which proved to be suitable ligands for hydroformylation and hydrocyanation reactions once coordinated to rhodium and nickel, respectively.…”

“…Recently, Pringle and his group have prepared remarkably stable fluorophosphines based on both phospha-adamantane cages and phosphabicycles, which proved to be suitable ligands for hydroformylation and hydrocyanation reactions once coordinated to rhodium and nickel, respectively. 4 Tri-fluorophosphine complexes of different metals (Pt, Ni) were prepared and characterised more than sixty years ago by Chatt 7 and G. Wilkinson 8 respectively, using highly drastic conditions, starting from the suitable metal precursor in the presence of high pressure of gaseous PF 3 (50-250 atm) and high temperature (above 100°C). Afterwards, J. F. Nixon, 9 prepared analogous complexes of different platinum group metals following a similar procedure.…”

Remarkable Differences in Amine Substitution Reactions of Trichloromethyl and Trifluoromethyl Difluorophosphines, CX3PF2(X = F, Cl): A Computational Study

“…and ) to the corresponding pentavalent fluorophosphorane, R n PF 5– n and polyphosphines unless the R group is strongly electron withdrawing (e.g. CF 3 ‐, C 3 F 7 ‐, C 6 F 5 ‐, CCl 3 ‐), sterically bulky (e.g., t Bu), or involves bicyclic systems typified by the phosphatrioxa‐adamantane cage . Almost five decades ago, one of us reported the remarkable and unexpected difference in behavior in the reaction between the trifluoromethyldifluorophosphine, CF 3 PF 2 , and secondary amines R 2 NH and the corresponding reaction involving the analogous trichloromethyl compound CCl 3 PF 2 .…”