A Broadly Applicable Copper Reagent for Trifluoromethylations and Perfluoroalkylations of Aryl Iodides and Bromides

An Improved Copper‐Mediated Oxidative Trifluoromethylation of Terminal Alkynes

“…), CuCl (2.0 equiv. ), and tBuOK in DMF, [13] and then 4-ethynylbiphenyl was added to the mixture in air at room temperature. Analysis of the reaction mixture by 19 F NMR spectroscopy demonstrated that a trace amount of the trifluoromethylation product was formed.…”

“…Liu, [10] Sheng, [11] and Xiao [12] documented the Cu I -catalyzed trifluoromethylation of boronic acids with electrophilic trifluoromethylation agents (Umemoto reagent and Togni reagent). Noteworthy is that Hartwig [13] and Grushin [14] recently prepared the trifluoromethylation Cu reagent [(phen)CuCF 3 ] and [(phen)Cu-(PPh 3 )(CF 3 )], respectively, both of which reacted with aryl iodides to afford trifluoromethylated arenes in high yields. Most of the aforementioned examples involved the preparation of CF 3 -substituted aryl compounds.…”

“…However, reaction temperatures up to 100°C and the requirement of 5.0 equivalents of TMSCF 3 rendered this methodology less than ideal (Figure 1). We assume that this oxidative trifluoromethylation reaction would be successful at room temperature by using fewer equivalents of TMSCF 3 if the (phen)Cu(CF 3 ) generated in situ from TMSCF 3 [13] was used (Figure 1). …”

Improved synthesis, structure, and reactivity of 1,4-bis(trimethylsilyl)octafluorobutane

“…Despite numerous attempts to prepare a perfluorometallocyclic compound (Scheme 1, f), or to use 1 in a perfluoroalkylation reaction, all of our efforts failed. For instance, when 1 was subjected to conditions commonly employed for transmetalation or perfluoroalkylation reactions (Scheme 2) [17,19,29], the major identifiable fluorine-containing species detected in all cases was 1,1,2,2,3,3,4,4-octafluorobutane. We have thus far been unable to use 1 to prepare the known [19], to perfluoroalkylate 2,3-diiodopyridine to form the known 5,5,6,6,7,7,8,8-octafluoro-5,6,7,8-tetrahydroquinoline [19], or to achieve dicupration with [Cu(O t Bu)] 4 and phenanthroline [29].…”

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

“…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. 43 The [44][45][46][47] Unfortunately, these reactions have a number of limitations, such as the requirement for high temperature (150−180 °C), lack of practicability, and poor substrate scope, despite their economical nature.…”