The hype about iodine(III): A chiral hypervalent iodine(III) reagent (1) is reported to enantioselectively dearomatize phenols in a highly selective manner (see scheme). This result clearly supports existence of the associative pathway in hypervalent iodine(III)‐induced phenolic oxidations.

Electrochemical reactions are shown to be effective for the C—H functionalization of a number of heterocyclic substrates that are recalcitrant to conventional peroxide radical initiation conditions. Monitoring reaction progress under electrochemical conditions provides mechanistic insight into the C—H functionalization of a series of heterocycles of interest in medicinal chemistry.

As oxidants, hypervalent iodine(iii) reagents are widely recognized as alternatives to highly toxic heavy-metal oxi-

A protic solvent, 2,2,2-trifluoroethanol (CF(3)CH(2)OH), was successfully introduced into hypervalent iodine(III)-involved catalytic cycles as an effective solvent, and the first iodoarene-catalyzed intramolecular carbon-nitrogen bond forming reaction was achieved under strong acid-free and mild conditions.

This report details the development of a spirobiindane-based chiral hypervalent iodine reagent, especially focusing on its structural elucidation for effective asymmetric induction of the chiral spiro center during the oxidative dearomatizing spirolactonization of naphthols. In this study we synthesized a new series of ortho-functionalized spirobiindane catalysts and demonstrated that the enantioselectivity can be dramatically improved by the presence of the substituents ortho to the iodine atom. The structural elucidation of a spirobiindane-based hypervalent iodine catalyst has led to further improvement in the stereoselective construction of the spiro center during the oxidative dearomatizing spirolactonization of naphthols. Thus, catalytic oxidation with the highest reported level of enantioselectivity in hypervalent iodine chemistry has been achieved with also an excellent level of asymmetric induction (92% ee for substrate 3a). As a result, this study, dealing with a series of modified iodine catalysts, can provide important clues about the transition state and reaction intermediate to help scientists understand the origin of the stereoselectivity. A plausible transition-state model and intermediate in the reaction for the stereoselective formation of spirolactone products are postulated by considering the ortho-substituent effect and the results of X-ray analysis. In this reaction model, the high enantiomeric excess obtained by using the spirobiindane catalysts could be well explained by the occupation of the equatorial site and extension of the surroundings around the hypervalent iodine bonds by the introduced ortho-substituent. Thus, this study would contribute to estimation of the chiral hypervalent iodine compounds in asymmetric reactions.