Recent discoveries on the structure of iodine(iii) reagents and their use in cross-nucleophile coupling

Abstract

This perspective article discusses structural features of iodine(iii) compounds as a prelude to presenting their use as umpolung reagents, to promote the selective coupling of two nucleophilic species via 2e− oxidation.

Diarylation of N- and O-nucleophiles through a metal-free cascade reaction

“…9 The increasing interest for sustainable, transition-metal-free transformations has spurred the development of hypervalent iodine-mediated arylations, primarily using diaryliodonium salts (Ar 2 IX). [10][11][12][13][14] These are easily available, bench-stable, and nonhazardous reagents that have proven to be efficient electrophilic arylation agents with a variety of O-and N-nucleophiles. 11,[15][16][17][18][19][20] Although reactions with…”

Chiral Hypervalent Iodine Catalysis Enables an Unusual Regiodivergent Intermolecular Olefin Aminooxygenation

“…Amide as the coupling reagent led to the formation of 3 as the only regioisomeric product in 60% yield and 93:7 e.r. On the other hand, acetonitrile and water as the nucleophiles in a Ritter-type reaction provided the opposite N, O-addition product 75 in 23% yield and 87:13 e.r. − Furthermore, oxazoline 3 could be derivitized to useful amino alcohol derivative and oxazole in good yields. , …”

Formal Enone α-Arylation via I(III)-Mediated Aryl Migration/Elimination

“…As part of our long-standing interest in the rearrangements of high-energy intermediates, we have established methodologies for the iodine­(III)-mediated α-arylation and α-cyclopropanation of carbonyl compounds through oxidative C–C bond activation and carbocationic rearrangements, respectively. Inspired by the outstanding ability of iodine­(III) in promoting oxidative rearrangements, we wondered whether this class of reagents could evoke an intramolecular α-arylation of enones. Herein we report a practical transition-metal-free protocol for the formal α-arylation of enones via iodine­(III)-mediated aryl migration/elimination.…”