Selectfluor-mediated mono-C–H activation: The syntheses of mono-ortho-substituted anilides

Relative Strength of Common Directing Groups in Palladium-Catalyzed Aromatic C−H Activation

“…N- phenylbenzamide ( 4 ) presents a perfect example of a system in which selectivity is highly influenced by reaction conditions (Figure 7). Although experimental studies seem to report contradictory results, some supporting reaction at position A (Boele et al., 2002, Zhu et al., 2018) and others illustrating functionalization at position B (Kametani et al., 2000, Chou et al., 2017), a closer scrutiny at reaction conditions easily rationalizes these divergent reactivity profiles. Under acidic conditions, where the amide is presumably present in its neutral form, transformations take place at position A.…”

Direct Arylation of C(sp2)–H Bonds in Anilines

“…This limitation was later overcome by the addition of a pyridine ligand substituted at the C3-position with an acetate group, 59 the use of mechanochemistry 60 or by applying Selectfluor™ as the oxidant in combination with D-camphorsulfonic acid. 61 Lastly, addition of an ortho-directing functional group on the arene of the coupling partner enabled selective ortho-C-H/ortho-C-H oxidative dehydrogenative cross-coupling reactions. 62 The selective ortho-arylation of anilides via oxidative cross-dehydrogenative cross-couplings is an attractive strategy and can deliver the target compounds in moderate to high yields with full control of the regioselectivity provided a directing group on each reactant is involved.…”

Recent Advances in the Application of Selectfluor as a “Fluorine‐free” Functional Reagent in Organic Synthesis

“…[4] Besides, other transition metal catalysts, such as, Ag, Cu, Fe and Pd could also be well oxidized by Selectfluor and applied in different organic synthesis. [10][11][12][13][14][15][16][17][18][19][20][21] In 2015, Qing and coworkers reported a novel method for the construction of alkyl trifluoromethyl ethers through Ag-promoted oxidative trifluoromethylation of alcohols with TMSCF3 in the presence of Selectfluor (Scheme 1a). [9] Following this study, the same group updated the reaction system to broaden the substrate scope.…”

“…A broad range of unactivated coupling partners, such as arenes, alkenes, and keto carboxylic acids, were used to prepare the corresponding aryl-, alkenyl-and keto-aryl amides (Scheme 10b). [21] Futhremore, a Selectfluor-promoted Pdcatalysed chemoselective dehydration reaction of primary amides to generate nitriles was reported by Croatt and coworkers (Scheme 11). [22] Although the role of Selectfluor was uncertain in the above system, the authors speculated that Selectfluor might be invovled in accelerating the catalytic cycle through the oxidation of a Pd(II) to Pd(IV) catalyst.…”