論文 - 宮本　和範

Direct transfer of the sulfonylimino group of imino-λ³- bromane to N-heterocycles and trialkylamines: Synthesis of N-iminoammonium ylides under metal-free conditions

Ochiai M., Kawano Y., Kaneaki T., Tada N., Miyamoto K.

Organic Letters （AMER CHEMICAL SOC）  11 （ 2 ） 281 - 284 2009年01月

査読有り,  ISSN  15237060

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(Chemical Equation Presented) Exposure of N-heterocycles and aliphatic trialkylamines to trifluoromethanesulfonylimino-λ3-bromane at room temperature results in direct transfer of the sulfonylimino group to the nitrogen atoms and affords a variety of iminoammonium ylides under transition-metal-free conditions. The imino-λ3-bromane probably serves as an active nitrenoid species without any activation and produces the ammonium ylides via a bimolecular nucleophilic substitution process. © 2009 American Chemical Society.

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Imido transfer of sulfonylimino-λ³-bromane makes possible the synthesis of sulfonylimino-λ³-iodanes

Ochiai M., Nakano A., Yoshimura A., Miyamoto K., Hayashi S., Nakanishi W.

Chemical Communications （Royal Society of Chemistry (RSC)）   （ 8 ） 959 - 961 2009年

査読有り,  ISSN  13597345

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Sulfonylimino-λ3-bromane functions as a reactive nitrenoid, because of the hyperleaving group ability of aryl- λ3-bromanyl groups, and undergoes transimidations to iodobenzenes at room temperature under metal-free conditions probably via an SN2-type nitrenoid transition state, yielding sulfonylimino- λ3-iodanes. © The Royal Society of Chemistry 2009.

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Thermal and catalytic transylidations between halonium ylides and synthesis and reaction of stable aliphatic chloronium ylides

Ochiai M., Tada N., Okada T., Sota A., Miyamoto K.

Journal of the American Chemical Society （AMER CHEMICAL SOC）  130 （ 7 ） 2118 - 2119 2008年02月

査読有り,  ISSN  00027863

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Intermolecular transylidation between halonium ylides under thermal and catalytic (rhodium(II) acetate) conditions, which makes it possible to synthesize a hitherto unknown kind of aliphatic chloronium ylides as well as a variety of bromonium and iodonium ylides, was developed. The uncatalyzed thermal transylidations of bromonium to iodonium ylides probably involve generation of a reactive carbene :C(SO2CF3)2, being electrophilic in nature. Compared to the bromonium and iodonium ylides, the chloronium ylide serves as a much better progenitor for generation of carbenes (or carbenoids) and efficiently undergoes cyclopropanation of olefins such as cyclooctadiene under uncatalyzed thermal conditions. A greater leaving group ability of the λ3-chloranyl and λ3-bromanyl groups compared to that of the λ3-iodanyl group seems to be responsible for the observed differences in reactivity between these halonium ylides. Copyright © 2008 American Chemical Society.

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A new type of imido group donor: Synthesis and characterization of sulfonylimino-Δ³-bromane that acts as a nitrenoid in the aziridination of olefins at room temperature under metal-free conditions

Ochiai M., Kaneaki T., Tada N., Miyamoto K., Chuman H., Shiro M., Hayashi S., Nakanishi W.

Journal of the American Chemical Society （American Chemical Society (ACS)）  129 （ 43 ） 12938 - 12939 2007年10月

査読有り,  ISSN  00027863

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A stable sulfonylimino-λ3-bromane, CF3SO2N--Br+C6H4-p-CF3, has been synthesized and structurally characterized for the first time. X-ray crystallographic analyses indicated a centrosymmetric dimer structure with little double-bond character for the "ylidic" Br-N bond. The iminobromane serves as an efficient imido group donor and directly undergoes aziridination of olefins stereospecifically with retention of original stereochemistry. Very interestingly, the aziridination proceeds at room temperature using limiting amounts of alkenes under transition-metal-free conditions. The observed rate constants for aziridination of cis-cyclooctene are proportional to concentration of the olefin. The results suggest the involvement of a bimolecular transition state, in which an olefin attacks the σ* N-Br orbital of iminobromane in the nitrenoid transfer process. Copyright © 2007 American Chemical Society.

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One-pot regioselective synthesis of chromanyl(phenyl)-λ³- iodanes: Tandem oxidative cyclization and λ³-iodanation of 3-phenylpropanols

Miyamoto K., Hirobe M., Saito M., Shiro M., Ochiai M.

Organic Letters 9 （ 10 ） 1995 - 1998 2007年05月

ISSN  15237060

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Reaction of 3-phenylpropanol with an activated iodosylbenzene - 18-crown-6 complex [Phl(OH)BF4-18C6] in dichloromethane in the presence of BF3-Et2O afforded directly the 6-chromanyl(phenyl)- λ3-iodane-18C6 complex through tandem oxidative intramolecular cyclization yielding chroman and its regioselectlve phenyl- λ3-iodanation. © 2007 American Chemical Society.

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Activated iodosylbenzene monomer as an ozone equivalent: Oxidative cleavage of carbon-carbon double bonds in the presence of water

Miyamoto K., Tada N., Ochiai M.

Journal of the American Chemical Society 129 （ 10 ） 2772 - 2773 2007年03月

ISSN  00027863

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Reported here for the first time are the developments of an efficient method for oxidative cleavage of carbon-carbon double bonds yielding carbonyl compounds by using aryl-λ3-iodanes, which involve a combination of iodosylbenzene and HBF4 in the presence of water. The method serves as a safety alternative to ozonolysis. The oxidative cleavage of olefins probably involves the hitherto unknown direct vicinal dihydroxylations of double bonds with aryl-λ3-iodanes and the subsequent oxidative glycol fissions. Cyclic (cyclopentenes, cyclohexenes, etc.) and acyclic olefins are cleaved smoothly under our conditions. In the reaction of electron-deficient styrenes such as m-nitrostyrene, intermediate formation of the corresponding epoxide was detected. A variety of aryloxiranes also undergo an oxidative cleavage of the epoxide rings under our conditions, and aromatic aldehydes were obtained in good yields. Copyright © 2007 American Chemical Society.

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trans influences on hypervalent bonding of aryl λ³- iodanes: Their stabilities and isodesmic reactions of benziodoxolones and benziodazolones

Ochiai M., Sueda T., Miyamoto K., Kiprof P., Zhdankin V.V.

Angewandte Chemie - International Edition 45 （ 48 ） 8203 - 8206 2006年12月

ISSN  14337851

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Large and small or twice moderate: Both combinations of trans influences of the substituents favor the formation of highly stable aryl λ 3-iodanes ArILL' (examples: PhI(OH)OTs and PhI(OAc)2). trans influences also seem to explain why iodosylbenzene adopts an oxo-bridged zigzag polymer structure in contrast to PhI(OH)2, which is monomeric. (Chemical Equation Presented). © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.

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Silver technology for stabilization of simple (Z)-enethiols: Stereoselective synthesis and reaction of silver (Z)-enethiolates

Ochiai M., Hirobe M., Miyamoto K.

Journal of the American Chemical Society 128 （ 28 ） 9046 - 9047 2006年07月

ISSN  00027863

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Reported here for the first time are the stereoselective synthesis and reaction of simple silver (Z)-enethiolates, which serve as stabilized (Z)-enethiol storage. In contrast to labile enethiols, silver (Z)-enethiolates are stable even in solutions, and their isolation and purification are very simple. The method for synthesis of silver (Z)-enethiolates involves an unusual vinylic SN2 reaction of (E)-vinyl-λ3-iodanes with thiobenzamides yielding the inverted (Z)-S-vinylthioimidonium salts, followed by their regioselective C-S bond cleavage with silver acetate. Alkylation, arylation, and Michael addition of silver (Z)-enethiolates yielding (Z)-vinyl sulfides were dramatically accelerated by the addition of Bu4NI (LiI), which probably generates reactive ammonium (Z)-enethiolates with an increased nucleophilicity. Copyright © 2006 American Chemical Society.

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Thiazole synthesis by cyclocondensation of 1-alkynyl(phenyl)- λ³-iodanes with thioureas and thioamides

Miyamoto K., Nishi Y., Ochiai M.

Angewandte Chemie - International Edition 44 （ 42 ） 6896 - 6899 2005年10月

ISSN  14337851

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(Chemical Equation Presented) The isolation and intramolecular cyclization of (S)-(1-alkynyl)isothiouronium and (S)-(1-alkynyl)thiobenzimidonium salts suggest the mechanism for the one-pot synthesis of 2,4-disubstituted thiazoles (see scheme; Ms = methanesulfonyl): Michael addition of sulfur nucleophiles to hypervalent iodanes followed by the 1,2-rearrangement of sulfenyl groups in the resulting alkylidene carbenes. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.

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Iodobenzene-catalyzed α-acetoxylation of ketones. In situ generation of hypervalent (diacyloxyiodo)benzenes using m-chloroperbenzoic acid

Ochiai M., Takeuchi Y., Katayama T., Sueda T., Miyamoto K.

Journal of the American Chemical Society 127 （ 35 ） 12244 - 12245 2005年09月

研究論文（学術雑誌）, 査読有り,  ISSN  00027863

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Reported here for the first time is the iodobenzene-catalyzed α-oxidation of ketones, in which diacyloxy(phenyl)-λ3-iodanes generated in situ act as real oxidants of ketones and m-chloroperbenzoic acid serves as a terminal oxidant. Oxidation of a ketone with m-chloroperbenzoic acid in acetic acid in the presence of a catalytic amount of iodobenzene, BF3·Et2O, and water at room temperature under argon affords an α-acetoxy ketone in good yield. p-Methyl- and p-chloroiodobenzene also serve as efficient catalysts in this direct oxidation. We found that when the reaction was carried out in the absence of a catalytic amount of iodobenzene, Baeyer-Villiger oxidation of a ketone took place. It is noted that use of water and BF3·Et2O is crucial to the success of this α-acetoxylation. Copyright © 2005 American Chemical Society.

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Effects of complexation with 18-crown-6 on the hypernucleofugality of phenyl-λ³-iodanyl groups. Synthesis of vinyl- λ³-iodane·18-crown-6 complex

Ochiai M., Suefuji T., Miyamoto K., Shiro M.

Organic Letters 7 （ 14 ） 2893 - 2896 2005年07月

研究論文（学術雑誌）, 査読有り,  ISSN  15237060

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(Chemical Equation Presented) 4-tert-Butyl-1-cyclohexenyl(phenyl) (tetrafluoroborato)-λ3-iodane forms a discrete supramolecular complex by the reaction with 18-crown-6. Solvolysis of the cyclohexenyl- λ3-iodane in the presence of 18-crown-6 indicates that the complexation with 18-crown-6 tends to decrease the leaving group ability of hypervalent phenyl-λ3-iodanyl groups. © 2005 American Chemical Society.

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Synthesis, characterization, and reaction of crown ether complexes of aqua(hydroxy)(aryl)iodonium ions

Ochiai M., Miyamoto K., Yokota Y., Suefuji T., Shiro M.

Angewandte Chemie - International Edition 44 （ 1 ） 75 - 78 2004年12月

研究論文（学術雑誌）, 査読有り,  ISSN  14337851

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Oxidation of 3-hydroxypiperidines with iodosylbenzene in water: Tandem oxidative grob fragmentation-cyclization reaction

Tada N., Miyamoto K., Ochiai M.

Chemical and Pharmaceutical Bulletin （PHARMACEUTICAL SOC JAPAN）  52 （ 9 ） 1143 - 1144 2004年09月

研究論文（学術雑誌）, 査読有り,  ISSN  00092363

　概要を見る

Oxidation of 3-hydroxypiperidine with iodosylbenzene in water afforded 2-pyrrolidinone directly in good yields. The reaction probably involves oxidative Grob fragmentation yielding imino aldehyde, which upon hydrolysis produces 2-pyrrolidinone via a cyclization-oxidation sequence. © 2004 Pharmaceutical Society of Japan.

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Synthesis and structure of supramolecular complexes between 1-alkynyl(phenyl)(tetrafluoroborato)-λ³-iodanes and 18-crown-6

Ochiai M., Miyamoto K., Suefuji T., Shiro M., Sakamoto S., Yamaguchi K.

Tetrahedron （PERGAMON-ELSEVIER SCIENCE LTD）  59 （ 51 ） 10153 - 10158 2003年12月

研究論文（学術雑誌）, 査読有り,  ISSN  00404020

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Slow evaporation of a solution of 1-decynyl(phenyl)(tetrafluoroborato)- λ3-iodane and 18-crown-6 in dichloromethane-diethyl ether-hexane gave a supramolecular 1:1 complex, while 3,3-dimethyl-1-butynyl- and phenylethynyl(phenyl)(tetrafluoroborato)-λ3-iodanes afforded 2:1 complexes. Complexation with 18-crown-6 increased the thermal stability of the phenylethynyl-λ3-iodane. Solid state and solution structures of these complexes were examined by single crystal X-ray analyses, 1H and 13C NMR spectra, and cold-spray ionization MS. Binding constants were measured by 1H NMR titrations. © 2003 Elsevier Ltd. All rights reserved.

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Isolation, Characterization, and Reaction of Activated Iodosylbenzene Monomer Hydroxy(phenyl)iodonium Ion with Hypervalent Bonding: Supramolecular Complex PhI⁺OH·18-Crown-6 with Secondary I⋯O Interactions

Ochiai M., Miyamoto K., Shiro M., Ozawa T., Yamaguchi K.

Journal of the American Chemical Society （AMER CHEMICAL SOC）  125 （ 43 ） 13006 - 13007 2003年10月

研究論文（学術雑誌）, 査読有り,  ISSN  00027863

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The isolation, characterization, and reaction of the active species hydroxy(phenyl)iodonium ion with hypervalent bonding are reported. Reaction of iodosylbenzene with HBF4-Me2O in the presence of equimolar 18-crown-6 in dichloromethane afforded the hydroxy-λ3-iodane complex PhI(OH)BF4·18-crown-6 as stable yellow prisms. X-ray structure analysis indicated that both the close contacts between the iodine(III) and the three adjacent oxygen atoms of 18-crown-6, and the hydrogen bonding OH⋯O(crown ether) will be responsible for the increased stability of the complex as compared to the uncomplexed PhI(OH)BF4. The crown ether complex is highly reactive and serves as a versatile oxidant even in water: thus, the complex undergoes oxidative transformations of a variety of functional groups such as olefins, alkynes, enones, silyl enol ethers, sulfides, and phenols under mild conditions. Copyright © 2003 American Chemical Society.

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Synthesis, characterization, and reaction of ethynyl(phenyl)-λ³-iodane complex with [18]crown-6

Ochiai M., Miyamoto K., Suefuji T., Sakamoto S., Yamaguchi K., Shiro M.

Angewandte Chemie - International Edition （WILEY-V C H VERLAG GMBH）  42 （ 19 ） 2191 - 2194 2003年05月

研究論文（学術雑誌）, 査読有り,  ISSN  14337851

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Iodine(III) crowned: Slow evaporation of solvents afforded the 1:1 complex 1 between [H-C≡C-I-Ph]BF4 and [18]crown-6 (18C6). Both the solid-state and solution structures of 1 were determined. Reaction of 1 with methanol proceeds in a Michael-type fashion. The complexation with 18C6 increases the stability of labile λ3-iodanes, such as 1.

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Synthesis of 1-alkynyl(diphenyl)onium salts of group 16 elements via heteroatom transfer reaction of 1-alkynyl(phenyl)-λ³-iodanes

Ochiai M., Nagaoka T., Sueda T., Yan J., Chen D.W., Miyamoto K.

Organic and Biomolecular Chemistry 1 （ 9 ） 1517 - 1521 2003年05月

研究論文（学術雑誌）, 査読有り,  ISSN  14770520

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1-Alkynyl(phenyl)-λ3-iodanes undergo selective transfer of the alkynyl groups over the phenyl group onto diphenyl chalcogens. Exposure of 1-alkynyl(phenyl)-λ3-iodanes to diphenyl chalcogens (S, Se, and Te) in dichloromethane or 1,2-dichloroethane affords 1-alkynyl(diphenyl)sulfonium, -selenonium, and -telluronium salts in high yields.

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Secondary hypervalent I(III)⋯O interactions: Synthesis and structure of hypervalent complexes of diphenyl-λ³-iodanes with 18-crown-6

Ochiai M., Suefuji T., Miyamoto K., Tada N., Goto S., Shiro M., Sakamoto S., Yamaguchi K.

Journal of the American Chemical Society （AMER CHEMICAL SOC）  125 （ 3 ） 769 - 773 2003年01月

研究論文（学術雑誌）, 査読有り,  ISSN  00027863

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Reported here for the first time are the synthesis and characterization of supramolecular complexes between diaryl-λ3-iodanes and 18-crown-6 (18C6). Slow evaporation of solvents afforded 1:1 and 2:1 complexes between Ph2IBF4 and 18C6 as stable crystals, depending on the conditions. X-ray crystal structures of these complexes indicated that each iodine atom contacts with the three adjacent oxygen atoms of 18C6 through two hypervalent secondary bonding and a weak interaction. 1H NMR analyses and CSI-MS spectra showed that, in dichloromethane solution, Ph2IBF4 exclusively forms the 1:1 complex with 18C6 (binding constant Ka, 1.02 x 103 M-1). The binding constants decrease with the increased solvent donor ability (Gutmann's DN). Changing the heteroatom ligand from BF4 to the less nucleophilic PF6 and AsF6 increased the binding constant by about six times. Substitution of an electron-withdrawing group onto the para position of Ph2IBF4 tends to increase in the complex stability. A linear Hammett relationship (p = 0.59) between log Ka and σp+ values of substituents indicates that the diaryl-λ3-iodanes with electropositive iodine(III) interact more efficiently with 18C6. Decreased binding magnitude was measured with 15C5, dibenzo-18C6, dibenzo-21C7, and dibenzo-30C10.

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Solid state structures of pentacoordinated λ³-iodanes with a trigonal bipyramidal geometry: Synthesis of diphenyl- and alkynyl(phenyl)-λ³-iodane complexes with 1,10-phenanthroline

Ochiai M., Suefuji T., Miyamoto K., Shiro M.

Chemical Communications 3 （ 12 ） 1438 - 1439 2003年

研究論文（学術雑誌）, 査読有り,  ISSN  13597345

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The single crystal X-ray structure of the supramolecular complex formed between diphenyl-λ3-iodane (Ph2IBF4) or 1-alkynyl(phenyl)-λ3-iodane [ButCCI(Ph)BF4] and 1,10-phenanthroline indicates a hitherto unknown distorted trigonal bipyramidal geometry around iodine(III), in which 1,10-phenanthroline acts as a bidentate ligand and occupies equatorial sites. © 2003 Royal Society of Chemistry.

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