Transformations based on direct excitation of hypervalent iodine(iii) reagents

Abstract

Hypervalent iodine compounds have evolved from structural curiosities into useful reagents owing to their unique polar and radical reactivity. In the last decade, many reactions based on their direct excitation...

Aliphatic Sulfonyl Fluoride Synthesis via Decarboxylative Fluorosulfonylation of Hypervalent Iodine(III) Carboxylates

“…However, all of these transformations need to use the electrophilic fluorination reagent N -fluorosulfonylimide (NFSI) or Selectfluor as the fluorine source. On the other hand, hypervalent iodine­(III) reagents enable radical decarboxylation of various carboxylic acids by in situ generation of carboxyl iodine­(III) species due to their mild single-electron oxidation reactivity . Inspired by these elegant developments and combined with our ongoing interest in sulfonyl fluoride synthesis via the RSIF strategy, herein, we present the decarboxylative fluorosulfonylation of various hypervalent iodine­(III) carboxylates with the use of the SO 2 surrogate 1,4-diazabicyclo[2.2.2]­octane–bis­(sulfur dioxide) adduct (DABSO) as the sulfonyl source and inexpensive nucleophilic KHF 2 as the desirable fluorine source under both photocatalysis and heating conditions, affording diverse aliphatic sulfonyl fluorides in good yields (Figure g).…”

Visible photons as ideal reagents for the activation of coloured organic compounds

“…70,71 Among hypervalent iodine(III) reagents, benziodoxoles are the only ones reported as photoreactive under visible-light irradiation and employed This journal is © The Royal Society of Chemistry 2024 in alkynylation processes. 72 Finally, both diselenides and ditellurides have a significant absorption tail in the visible region (400-550 nm), which has been assigned to the ns* transition band, [73][74][75] which is responsible for inducing Se-Se and Te-Te bond cleavage. In some instances, visible-light is an important tool for the uncaging of functional groups.…”

Triplet Energy Transfer Mechanism in Copper Photocatalytic N‐ and O‐Methylation

“…[7] Likewise, direct photo-chemical excitation of hypervalent iodine reagents was applied in group transfer reactions. [8] On the one hand, single-electron transfer (SET) or reduction of PIDA can occur from highly reducing excited state photocatalysts (PC, Figure 1). On the other hand, access to triplet states of PIDA is feasible due to the heavy-atom effect of iodine and can be reached via direct Dexter-type energy transfer of long-lived triplet excited states of the photocatalyst.…”

“…A suitable activation method for carboxylic acids are hypervalent iodine(III) reagents, such as phenyliodo diacetate (PIDA), which are well known sources for aliphatic radicals [6] and have been activated with photochemistry in chain reactions [7] . Likewise, direct photochemical excitation of hypervalent iodine reagents was applied in group transfer reactions [8] …”