Sandmeyer Trifluoromethylation of Arenediazonium Tetrafluoroborates

Abstract

Copper capabilities: Diazonium salts are converted into the corresponding trifluoromethyl derivatives in the presence of a trifluoromethyl–copper complex generated in situ from CuSCN and the inexpensive, easy‐to‐use trifluoromethylating reagent Me3Si‐CF3 (see scheme). This Sandmeyer‐type reaction allows the straightforward synthesis of trifluoromethylated arenes and heteroarenes from the corresponding amines.

Antagonistic Effect of Acetates in C–N Bond Formation with In Situ Generated Diazonium Salts: A Combined Theoretical and Experimental Study

“…trifluoromethylation and trifluoromethylthiolation of arenediazonium tetrafluoroborates have also been reported recently. [21,22] It may also be noted that the direct reaction of diazonium salts with amines, which proceeds by a radical mechanism, has also been reported in the literature. [23] Some of us [24] recently reported the first copper-catalyzed C-N bond-formation reaction involving arenediazonium salts.…”

“…The Cu I catalyst reacts with the diazonium salt according to either (a) an oxidative addition [49][50][51] or (b) a single-electron transfer [21,22,52] (SET; from the metal species or from another reductive agent source) with loss of the N 2 group as a gas. The choice between paths (a) and (b) is usually motivated by a radical-clock experiment or by a control experiment in the presence of a radical scavenger.…”

Recent advances in green fluorine chemistry

“…In 2013, Dai et al, 70 Danoun et al, 71 and Wang et al 72 reported the Sandmeyer-type trifluoromethylation of aryl diazonium salts (Figure 32). Although these reactions are carried out similarly, different mechanisms have been proposed in their reports.…”

Hydrotrifluoromethylation and iodotrifluoromethylation of alkenes and alkynes using an inorganic electride as a radical generator

“…In particular, trifluoromethylated compounds are characterized by superior metabolic stability, binding selectivity, bioavailability and lipophilicity compared with those of their nontrifluoromethylated analogues, and these characteristics have stimulated the intensive development of new pharmaceutical and agrochemical agents bearing this moiety [3][4][5] . In general, transition-metal-catalysed cross-coupling reactions (for example, those involving Cu, Pd, Ru or Ir) are regarded as state-of-the-art methods for C-CF 3 bond formation [6][7][8][9][10][11][12][13][14][15][16][17][18] . However, these transition-metal-catalysed reactions pose their own challenges.…”