Nickel-Catalyzed Carbonylation of Difluoroalkyl Bromides with Arylboronic Acids

Abstract

A nickel-catalyzed carbonylative difluoroalkylation reaction with arylboronic acids under 1 atm of CO has been developed. The reaction proceeds under mild reaction conditions with high efficiency and high functional group tolerance. Preliminary mechanistic studies reveal that the arylacyl nickel complex is the key intermediate to circumvent the formation of labile fluoroacyl nickel, and bimetallic oxidative addition is likely the key step to facilitate the catalytic cycle.

Solvated Nickel Complexes as Stoichiometric and Catalytic Perfluoroalkylation Agents**

“…Such compounds were easily prepared by the addition of "A g-R f " to [(dme)NiBr 2 ]i na cetonitrile solvent in the presence of [NMe 4 ]Cl. The 19 FNMR spectrum of 5 displays four signals with integrations consistent with two perfluoroethyl groups cis to the acetonitrile group and one perfluoroethyl group that is trans to the acetonitrile.T he CF 3 resonance that is trans to the coordinated acetonitrile appears as aquintet from the 5 J FF coupling of the other two CF 2 groups,while the resonance for the CF 3 groups that are cis to the acetonitrile appear as at riplet. Thea bsence of 3 J FF coupling is common for perfluoroalkyl groups and is suggested to arise from the rotational averaging of coupling constants of opposite sign between the vicinal CF 2 and CF 3 groups.…”

Solvated Nickel Complexes as Stoichiometric and Catalytic Perfluoroalkylation Agents**

“…Nickel is a promising platform for developing practical fluoroalkylation methodologies as fundamental steps relevant to chemical bond forming reactions have been established. Reductive eliminations involving fluoroalkyl groups have been demonstrated at higher valent states of nickel, [1–4] the generation of fluoroalkyl radicals via electron transfer or atom abstraction reactions of fluoroalkyl electrophiles with nickel is known, [5–12] fluoroalkyl‐based transmetalating reagents readily react with nickel, [13–15] and catalytic transformations involving select fluoroalkyl groups have been reported [6, 10–13, 16–21] . Nickel is also an earth‐abundant metal with a reasonably low cost.…”

Study on Rh(I)/Ru(III) Bimetallic Catalyst Catalyzed Carbonylation of Methanol to Acetic Acid

“…Bimetallic complex catalysts with heteronuclear structures are often used to show better performance than single-metal catalysts through metal–metal interactions and their ligand effects [ 14 , 15 , 16 ]. As a result, the catalyst has become a research hotspot [ 17 , 18 , 19 , 20 , 21 , 22 ]. The bridged ligand and Rh coordinate to form a bidentate coordination structure, and after the ligand is coordinated with Rh, it can firmly grasp Rh.…”