Synthesis of 4‐Methylbenzoate(2′,4′,6′‐Trimethoxy‐Phenyl)Iodonium Tosylate

Abstract

This article describes the procedure for synthesis of 4‐Methylbenzoate(2’,4’,6’‐trimethoxyphenyl)iodonium Tosylate. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. Unsymmetrical diaryliodonium salts that selectively, and predictably, transfer one aryl group over the other are particularly desirable reagents, especially for the transfer of elaborate aryl groups to nucleophilic moieties. Aryl(trimethoxyphenyl)iodonium tosylates undergo facile anion exchange with other anions under aqueous conditions to generate the corresponding aryl(trimethoxyphenyl)iodonium bromides, iodide, trifluoroacetates, triflates, tetrafluoroborates, and hexafluorophosphates. The article also describes the hazards associated with working with chemicals and the ways to deal with these hazards.

Anion Metathesis of Diaryliodonium Tosylate Salts with a Solid-Phase Column Constructed from Readily Available Laboratory Consumables

“…We previously assessed the thermal stability of the reagents (methyl-4-iodobenzoate), oxidant ( m -CPBA), intermediate ([hydroxyl­(tosyloxy)]­iodo arene), and product ( 1 -OTs) in a large scale (50 mmol) synthesis by differential scanning calorimetry (DSC) . Here, we expand the safety analysis to include other iodonium salts with different aryl substituents and counteranions.…”

“…In our own research on method development with aryl­(TMP)­iodonium salts, we have typically noted that the highest yields are obtained between 50–80 °C. We emphasize that large scale operations should be carried out with caution, although we also recognize the critical role that solvent can play in dilution and heat transfer . An example of the benefit is that for the metathesis reported here, we anticipate the heat of reaction to be below 20 kJ/mol .…”

“…arene), and product (1-OTs) in a large scale (50 mmol) synthesis by differential scanning calorimetry (DSC). 7 Here, we expand the safety analysis to include other iodonium salts with different aryl substituents and counteranions. Table 2 lists the initiation temperature and magnitude of the exothermic event observed upon heating these reagents as neat solids in a closed crucible, and we discerned several general trends from the data.…”

Diaryliodoniums Salts as Coupling Partners for Transition-Metal Catalyzed C- and N-Arylation of Heteroarenes

“…Diaryliodonium salts are air-and moisture-stable, non-toxic, easy to handle and commercially available or easy to prepare [1][2][3][4][5][6][7][8]. During the last decade, noteworthy improvement in the synthesis and use of diaryliodonium salts has been reported [9][10][11][12][13][14][15][16][17][18][19][20][21]. Owing to their electron-deficient nature at the iodine center and to the excellent leaving-group ability of the iodoarene, diaryliodonium salts are frequently employed as aromatic electrophiles in aryl transfer processes [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

Recent Advances in Transition-Metal-Free Late-Stage C-H and N-H Arylation of Heteroarenes Using Diaryliodonium Salts

“…In the last decade, recent progress in this area has been achieved including selective C-H and N-H arylations of heteroarenes using non-toxic and easy-to-handle diaryliodonium salts as aromatic electrophiles [ 39 , 40 , 41 , 42 ]. Most of the arylation reactions show high functional group tolerance and involve a symmetric diaryliodonium salt or a non-symmetric bearing an inert coupling auxiliary, also called a “dummy” group, such as TMB (2,4,6-trimethoxyphenyl), Mes (2,4,6-methylphenyl), TRIP (2,4,6-tri iso propylphenyl) or uracil [ 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 ]. This review provides an overview of the recent developments and early examples of arylating heteroarenes under metal-free conditions using acyclic diaryliodonium salts as coupling partners.…”