Synthesis, characterisation, and reactivity of novel pseudocyclic hypervalent iodine reagents with heteroaryl carbonyl substituents

Abstract

New heteroatom-containing pseudocyclic iodanes are being introduces as alternatives to the Koser reagent.

Pseudocyclic Bis-N-Heterocycle-Stabilized Iodanes – Synthesis, Characterization and Applications

“…With its high reactivity, BNHI 12b appears to be among the most potent pseudocyclic  3 -iodanes reported so far for this oxidation. [12][13][14]20,31,33 Due to these promising results, we were eager to investigate the versatility and potency of 12b in a variety of other oxidative transformations (Scheme 3, a-f). 2,3-Dimethylhydroquinone (21) was efficiently oxidized to pchinone 22 in 90% yield in only one minute.…”

“…Furthermore, for the oxidative cyclization of thiobenzamide (26) again outstanding reactivity was observed, yielding thiadiazole 27 in 99% after only one minute. 12,14,20,31 In the iodination of arenes (Scheme 3, d), iodomesitylene (29a) and 1-iodo-2,4,6triisopropylbenzene (29b) were obtained in 58-64% from the corresponding arenes. However, with increased equivalents of Bis-Pyr-I-OTf 12b and iodine the triisopropyl derivative 29b was obtained in quantitative yield.…”

Synthesis of arylbenziodoxoles using pseudocyclic benziodoxole triflate and arenes

“…20,21 Most of these compounds have higher stability and improved reactivity in comparison to their respective non-cyclic hypervalent iodine(III) reagents. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Previously, our group has reported the preparation, structure, and reactivity of 2-[hydroxy(trifluoromethanesulfonyloxy)]-iodobenzoic acid (IBA-TfOH), which is the pseudocylcic analogue compound of [hydroxy(trifluoromethanesulfonyloxy)iodo]benzene PhI(OH)OTf. [37][38][39][40] The novel IBA-TfOH reagent showed better reactivity as well as higher stability than PhI(OH)OTf.…”

Sulfur-Based Chiral Iodoarenes: An Underexplored Class of Chiral Hypervalent Iodine Reagents

“…100 Å) between the sulfoximine nitrogen [(N(1)] and the iodine centre [I(1)] which is shorter than the iodineoxygen bond [I(1)-O(2), 2.249 Å]. The observed angle [N(1)-I(1)-O(2)] of compound 24 (167.15°) is in the range of the distorted T-shaped geometry characteristic to λ 3 -iodanes 30,46. …”