Synthesis of arylbenziodoxoles using pseudocyclic benziodoxole triflate and arenes

Abstract

An acid activated pseudocyclic hypervalent iodine reagent, 2-[hydroxy(trifluoromethanesufonyloxy)]iodobenzoic acid, can easily react with various arenes in the presence of trifluoromethanesulfonic acid to produce pseudocyclic diaryliodonium triflate salts. This synthetic procedure proceeds under mild conditions to afford the respective iodonium salts in moderate to good yields. Several pseudocyclic diaryliodonium triflate salts structures have been confirmed by X-ray crystallography. Obtained products can be easily converted to cyclic hypervalent iodine(III) compounds, arylbenziodoxolones, in moderate to good yields under basic conditions.

Organohypervalent heterocycles

“…436,443–445 Arylbenziodoxoles have been shown to possess a zwitterionic structure, as evidenced by the presence of a short internal interaction between iodine and oxygen atoms. 436–438,440–443 Further, the average distance of the intramolecular I⋯O bonds (2.5 Å) is longer compared to the average covalent I–O bond length (2.14 Å); 446,447 however, shorter than the sum of van der Waals radii for iodine atom and oxygen atoms (3.5 Å), 448 indicating a significant increase in the ionic nature of this bond.…”

“…Moreover, these compounds can also be obtained from suitable hypervalent iodine reagents through ligand exchange reaction. [440][441][442] Single-crystal X-ray structures of several arylbenziodoxoles have been published. 436,[443][444][445] Arylbenziodoxoles have been shown to possess a zwitterionic structure, as evidenced by the presence of a short internal interaction between iodine and oxygen atoms.…”

Aryl-, Akynyl-, and Alkenylbenziodoxoles: Synthesis and Synthetic Applications

“…Later, IBA-TfOH 10 (IBA = 2-iodosylbenzoic acid) and arenes 11 have been used as starting materials for the preparation of pseudocyclic arylbenziodoxole triflates 12 in the first step followed by treatment of compounds 12 with a saturated NaHCO 3 solution at room temperature to afford desired arylbenziodoxoles 2, with the yields up to 100% (Scheme 3c) [28].…”

“…Single-crystal X-ray structures have been published for several arylbenziodoxoles 2 [23,[29][30][31]. According to single-crystal X-ray diffraction data, arylbenziodoxoles 2 have a zwitterionic structure characterized by the presence of a short internal I•••O interaction [23][24][25][26][27][28][29]. The average distance of the intramolecular I•••O bonds (2.5 Å ) is longer than the average covalent I-O bond length (2.14 Å ) [32,33] but shorter than the sum of van der Waals radii for iodine atom and an oxygen atom (3.5 Å ) [34], which is indicative of a significant increase in the ionic nature of this bond.…”

Introduction to hypervalent iodine chemistry. Part 3

“…Part 1 (2020) and Part 2 (2021) contain total 20 papers covering a broad range of topics of the HI chemistry. Specific topics of these papers include the following: theoretical and computational studies of HI compounds, [2][3][4] structural studies, 5 development of new synthetic approaches to HI reagents, [6][7][8][9] photochemical reactions involving HI chemistry, 10,11 industrial applications of hypervalent polyiodides, 12 and numerous synthetic applications of HI reagents. [13][14][15][16][17][18][19][20] Part 3 of the HI series will be published in 2022 covering all topics of iodine chemistry involving hypervalent species and halogen bonding.…”