The solid complex Zn(CF3)Br·2DMF as an alternative reagent for the preparation of both, trifluoromethyl and pentafluoroethyl copper, CuCF3 and CuC2F5

Cu-catalyzed trifluoromethylation of aryl iodides with trifluoromethylzinc reagent prepared in situ from trifluoromethyl iodide

“…The reaction mixture was stirred at 50 °C for 24 h. After cooling to room temperature, the yield of product 2a was determined by 19 F NMR analysis by using benzotrifluoride (BTF) as an internal standard. Except for 2c , all trifluoromethylated products 2 exhibited the same 1 H, 13 C, and 19 F NMR spectra as reported before [14,17,29,31–36]. …”

“…At the initial stage, Zn(CF 3 )I which readily causes a Schlenk equilibrium with Zn(CF 3 ) 2 and ZnI 2 [14,24] was prepared in situ from CF 3 I and Zn dust in 60–80% yields in both solvents. The addition of CuI (0.2 equiv) to a DMPU solution of Zn(CF 3 )I led to the transmetallation of the CF 3 group from zinc to copper even at room temperature.…”

“…In contrast, trifluoromethylsilyl counterparts, so-called Ruppert–Prakash reagents (CF 3 SiR 3 ), are highly stable, but reactive in the presence of fluoride, and hence the most versatile nucleophilic trifluoromethyl reagents [11–12]. The trifluoromethylzinc reagent (Zn(CF 3 )Br·2DMF), a stable solid, can also be used for the trifluoromethylation of aryl iodides, while stoichiometric amounts of copper(I) bromide are required to afford the more reactive trifluoromethyl copper (CuCF 3 ) species by transmetallation [13–14]. However, these reagents are generally prepared from trifluoromethyl bromide (CF 3 Br), whose production is now prohibited because of the ozone depleting effect [15].…”

Copper‐Catalyzed Aromatic Trifluoromethylation via Group Transfer from Fluoral Derivatives

“…Trifluoromethylcopper (CF 3 Cu), which is unstable and needs to be generated in situ , acts as a prominent cross‐coupling participant of aromatic trifluoromethylation 5–8. In order to generate CF 3 Cu species, there have been several protocols using CF 3 I/Cu,5a–d CF 3 Br/Cu‐anode,5e CF 3 N(NO)Tf/Cu,5f CF 2 Br 2 /Cu/DMAc,5g,h (CF 3 ) 2 Hg/Cu,5i CF 3 CdX/CuX,5j,k CF 3 ZnX/CuX,5j–l CF 3 SO 2 Cl/Cu,5m FSO 2 CF 2 CO 2 Me/CuI,5n FSO 2 CF 2 CF 2 OCF 2 CO 2 Me/CuI,5o CF 3 CO 2 Na/CuI,5p,q CF 3 CO 2 Me/CsF/CuI,5r ClCF 2 CO 2 Me/KF/CuI,5s CF 3 SiEt 3 /KF/Cu,5t,u and [CF 3 SPh 2 ] + OTf − /Cu 5w. For most of the aromatic trifluoromethylations using CF 3 Cu, stoichiometric (sometimes, excess) amounts of copper reagents are required to complete the cross‐coupling reactions 5a–m,o–v,6–8.…”

A class of effective decarboxylative perfluoroalkylating reagents: [(phen)2Cu](O2CRF)

“…[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] There is, however, few examples for the introduction of the longer-chain perfluoroalkyl moieties, such as the C 2 F 5 group, into organic molecules (Scheme 2). 36,37,38 For instance, Hartwig and coworkers successfully employed stable (phen)Cu(C 2 F 5 ), prepared from reaction of CuOt-Bu with C 2 F 5 SiMe 3 , for pentafluoroethylation of arylboronate esters and heteroaryl bromides. [39][40][41] Grushin's groups reported the ligandless Cu(C 2 F 5 ) in situ prepared by the direct cupration of economical C 2 F 5 H 42 and Mikami's groups later reported the same reagent synthesized from ethyl pentafluoropropionate.…”