Iodoarene-catalyzed oxidative transformations using molecular oxygen

Miyamoto, Kazunori; Yamashita, Junzo; Narita, Shodai; Sakai, Yasufumi; Hirano, Kiyotaka; Saito, Taro; Wang, Chao; Ochiai, Masahito; Uchiyama, Masanobu

doi:10.1039/c7cc05160c

Cited by 49 publications

(31 citation statements)

References 60 publications

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“…The Miyamoto-Uchiyama protocol requires a sterically hindered aldehyde and was applied to the glycol scission of 1,2-diols and the Hofmann rearrangement of primary amides with only 3 to 5 equivalents of isobutyraldehyde and 5 to 20 mol % of pentamethyliodobenzene. [23] Powers method, which was further refined for the formation of iodine(V) reagents, [28] uses 10 equivalents of acetaldehyde and 1 mol % of CoCl 2 as the initiator to promote the synthesis of (diacetoxy)iodoarenes from the corresponding aryl iodides in acetic acid. This system was named "oxidase catalysis" by the authors.…”

mentioning

confidence: 99%

Photoinduced Aerobic Iodoarene‐Catalyzed Spirocyclization of N‐Oxy‐amides to N‐Fused Spirolactams**

Habert

Cariou

2020

Angew Chem Int Ed

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We report that the spirocyclization of N-oxy-amides to N-fused spirolactams can be achieved under photoinduced aerobic conditions, using a dual iodoarene/pyrylium catalytic system. 13 spirolactams were obtained in this manner and control experiments have shown that the reaction does not proceed if either one of the catalyst is omitted or in the absence of light and/or oxygen. INTRODUCTION: Hypervalent iodine(III) compounds have been known for 130 years, 1 yet interest in their reactivity was very modest until the eighties, before witnessing a dramatic surge in the 2000's. 2-4 They possess many advantages in terms of versatility, high selectivity and lack of toxicity; however, their use as a stoichiometric reagent remains a drawback. Indeed, the driving force behind their reactivity is the final release of one equivalent of iodoarene (Scheme 1a), such as iodobenzene. The liberation of a stoiC 50 and HFIP-derived D (Scheme 5b). For Kita's bis iodoarene catalyst, 38 the stabilization would come from the formation of µ-oxo species. CONCLUSION: Using the spiro-cyclization of amides as a model reaction, we have demonstrated that aerobic iodoarene catalysis can be enabled by relying on a pyrylium photocatalyst under blue light irradiation. This unprecedented dual organocatalytic system allows the use of low catalytic loading of both catalyst under very mild operating conditions. We are currently pursuing more thorough study of this dual catalyst system to gain a deeper understanding of the reaction parameters by experimental and theoretical methods. This will allow us to expand the range of transformations that can be accomplished using this strategy, including the development of asymmetric reactions. ASSOCIATED CONTENT Supporting Information includes, optimization studies and control experiments, detailed synthetic procedures, characterizations of the compounds and copies of the NMR spectra. This material is available free of charge via the Internet at http://pubs.acs.org.

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confidence: 99%

Photoinduced Aerobic Iodoarene‐Catalyzed Spirocyclization of N‐Oxy‐amides to N‐Fused Spirolactams**

Habert

Cariou

2020

Angew Chem Int Ed

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“…Contemporaneously, Miyamoto and Uchiyama et al. reported iodoarene‐catalyzed aerobic glycol cleavage reactions and Hofmann rearrangements under similar aldehyde‐promoted aerobic oxidation conditions . We reasoned that the scope of aerobic oxidation chemistry that can be achieved via hypervalent iodine intermediates would be substantially expanded if the aerobic oxidation of iodobenzenes could be extended to the synthesis of I(V) reagents (iodylbenzenes, 3 ) .…”

Section: Methodsmentioning

confidence: 99%

“…[5] Contemporaneously,Miyamoto and Uchiyama et al reported iodoarene-catalyzed aerobic glycol cleavage reactions and Hofmann rearrangements under similar aldehyde-promoted aerobic oxidation conditions. [6] We reasoned that the scope of aerobic oxidation chemistry that can be achieved via hypervalent iodine intermediates would be substantially expanded if the aerobic oxidation of iodobenzenes could be extended to the synthesis of I(V) reagents (iodylbenzenes, 3). [7] I(V) reagents, [8] such as Dess-Martin periodinane (DMP) [9] and 2-iodoxybenzoic acid (IBX), [10] display complementary substrate oxidation chemistry as compared to iodosylbenzenes (2), and have been applied to the oxidation of primary and secondary alcohols, [9,11] 1,2- [12] and 1,4-diols, [13] and amines, [14] as well as the dehydrogenation of carbonyl compounds to generate a,b-unsaturated carbonyls, [15] and benzylic CÀHb ond oxidation.…”

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confidence: 99%

Oxidation Catalysis by an Aerobically Generated Dess–Martin Periodinane Analogue

et al. 2018

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Hypervalent iodine(V) reagents, such as Dess-Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to generate these reagents from dioxygen (O ) would immediately enable use of O as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. In this work, aerobic oxidation of iodobenzenes is coupled with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. The developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.

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“…In 2017, Miyamoto and co-workers initially reported the facile auto-oxidation of isobutyraldehyde 1a under a dioxygen atmosphere (use of balloon) in 1,2-dichloroethane at 40°C in which perisobutyric acid 29 was the predominant species present after 1 h. 27 Further reaction upon addition of iodobenzene 30 proceeded efficiently, granting a 75% yield of hypervalent iodine(III) species 31 after 5 h (Scheme 11). Miyamoto and co-workers then used this procedure of generating hypervalent iodine(III) intermediates to effectively carry out oxidative cleavage of 1,2-diols and Hofmann rearrangement of carboxamides.…”

Section: Aldehydesmentioning

confidence: 99%