Copper-Catalyzed Regioselective C-H Sulfonyloxylation of Electron-Rich Arenes with p-Toluenesulfonic Acid and Sulfonyloxylation of Aryl(mesityl)iodonium Sulfonates

Abstract

Copper-catalyzed regioselective C-H sulfonyloxylation of electron-rich arenes with p-toluenesulfonic acid has been developed. Electron-rich benzene derivatives and heteroarenes can undergo this C-H sulfonyloxylation reaction to generate aryl tosylates. Furthermore, sulfonyloxylation of aryl(mesityl)iodonium sulfonates has also been investigated. Both aryl(mesityl)iodonium tosylates and triflates can react smoothly to get aryl sulfonates. The formed aryl sulfonates can be converted to phenols, as well as used as good partners of cross-coupling reactions.

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

“…On the other hand, such heterocyclic moieties present in bioactive compounds, or their synthetic intermediates may eventually play the role of a directing group, thus providing an opportunity for convenient and straightforward transformations based on metal-mediated C-H activation [314]. Many methods potentially useful for the synthesis or modification of bioactive compounds based on copper-promoted activation of C-H bonds in (hetero)arenes have been reported in the last years, including methods for the formation of C-C [304][305][306][307][308][309][310][311][312], C-X [315][316][317][318][319], C-N [305,[320][321][322][323][324], C-O [325][326][327][328][329][330], and C-S [324,331,332] bonds. Some of these methods are highlighted herein.…”

“…Another example of the usefulness of a copper-mediated C-H activation reaction was reported by Duan, Zhang and co-workers in the synthesis of polycyclic 2-quinolinones, which are scaffolds present in bioactive alkaloids, such as orixalone D, mertinellic acid and meloscine (Scheme 77A) [321]. By using Cu(OAc) 2 in substoichiometric amount, O 2 as oxidant, and Kobayashi aryne precursors, the coupling of acrylamides derived from 8-aminoquinoline and arynes could be achieved with moderate to good yields, including three core skeletons of Copper has been reported to be useful in C-O bond-formation reactions involving C(sp 2 )-H activation for the introduction of tosyl-, hydroxy-, acyloxy-, alkoxy-, and aryloxy groups into arenes [324][325][326][327][328]330]. A copper-based method was reported by Punniyamurthy and co-workers who applied a copper-based method to the synthesis of naphthyl aryl ethers, which are motifs featured by bioactive compounds, such as the antimalarial drug tafenoquine (248) (Scheme 78A) [329].…”

N1‐ and N3‐Arylations of Hydantoins Employing Diaryliodonium Salts via Copper(I) Catalysis at Room Temperature

“…In the case of À OTs iodonium salt, Oarylation at the tosyl group was primarily observed which is opposite to Sandtorv's result. [20] Nevertheless, O-arylation is possible with À OTs, [21] but À OTs acts as a good counter anion depending on the reaction conditions both in metal-free and metal-catalyzed reactions. [20,22] Our Cu-catalysed version of Narylation of hydantoins was achieved because of the lesser nucleophilicity of the diaryliodonium triflate.…”

Recent Advances in Copper(II)-Mediated or -Catalyzed C–H Functionalization

“…Xiang and co-workers developed a copper-catalyzed regioselective C-H sulfonyloxylation reaction of electron-rich arenes with 4-toluenesulfonic acid (Scheme 51). 45 Electronrich benzene derivatives and heteroarenes afforded the cor-…”