Ru‐Catalyzed Oxidations with Iodosylbenzene Derivatives. Substituent Effects on Selectivity in Oxidation of Sulfides and Alcohols

Abstract

SummaryOxidation of sulfides with Ph1O/RuCl2 (PPh& leads to sulfones. Electronwithdrawing substituents in the aromatic ring of PhIO reduce the reactivity and improves selectivity of the system. Thus, with m-iodosylbenzoic acid sulfides are converted to suhfoxide. Under the same conditions aliphatic primary alcohols are transformed to aldehydes with m-iodosylbenzoic acid, while PhIO affords carboxylic acids. Introduction. -We have already reported on catalyzed oxidations with iodosylbenzene (PhIO) and alcohols [I], alkynes [2] and alkynyl ethers and amines [3].Other investigators have since published results for oxidations with high-valent organoiodine compounds. Thus conversion of sulfides into sulfoxides was accom-

Oxidase catalysis via aerobically generated hypervalent iodine intermediates

“…Substitution of the aromatic ring has been demonstrated to provide a synthetic handle to tune both the activity and the aggregation state of aryl I(III) reagents. 36,37 Addition of TsOH to the oxidation of PhI affords Koser's reagent (3), 38 an acidactivated iodosylbenzene derivative, in 84% yield. Similarly, addition of carboxylic acids to the reaction mixture directly affords the corresponding I(III) esters: oxidation in the presence of trifluoroacetic acid (TFA) and benzoic acid results in PhI(TFA)2 and PhI(OBz)2 in 52% and 48% yields, respectively.…”

NMR study on the structure and stability of 4‐substituted aromatic iodosyl compounds

“…1,18 The oxidation of primary alcohols, for example, in the presence of a ruthenium catalyst has been reported. 19 The disproportionation of 2 into 4-nitro-iodylbenzene and 1-iodo-4-nitro-benzene 15 could not be observed; the corresponding aromatic proton signals in the 1 H NMR were absent. 1-Iodosyl-4-methoxy-benzene was less reactive towards methanol; after 24 h at r.t., the 1 H NMR spectrum remained unchanged and only 18% of 1 was converted to 1-iodo-4-methoxy-benzene after warming for 1.5 h at 60°C.…”