The Experts below are selected from a list of 3816 Experts worldwide ranked by ideXlab platform
Yasuyuki Kita - One of the best experts on this subject based on the ideXlab platform.
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μ oxo bridged hypervalent iodine iii compound as an extreme oxidant for aqueous oxidations
Synthesis, 2012Co-Authors: Toshifumi Dohi, Tomofumi Nakae, Naoko Takenaga, Teruyoshi Uchiyama, Keiichiro Fukushima, Hiromichi Fujioka, Yasuyuki KitaAbstract:We have found that in aqueous oxidations the μ-oxo-bridged hypervalent iodine Trifluoroacetate reagent 1 {[(PhI(OCOCF3)]2O} is generally more reactive than the corresponding monomeric reagent, especially toward phenolic substrates. μ-Oxo-bridged 1 in aqueous media thus provided dearomatized quinones 3 in excellent yields in most cases compared to conventional phenyliodine(III) diacetate and bis(Trifluoroacetate), as a result of the rapid oxidation of both phenols and naphthols 2. Furthermore, the oxidation reactions proceeded even in water using water-soluble μ-oxo oxidant 1, which has promise for μ-oxo-bridged reagent 1 to become the favored reagent over hydrophobic phenyliodine(III) diacetate and bis(Trifluoroacetate).
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a novel and efficient oxidative biaryl coupling reaction of phenol ether derivatives using a combination of hypervalent iodine iii reagent and heteropoly acid
Chemical Communications, 2002Co-Authors: Hiromi Hamamoto, Hirofumi Tohma, Gopinathan Anilkumar, Yasuyuki KitaAbstract:A novel and efficient oxidative biaryl coupling reaction of phenol ether derivatives using a combination of hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate) (PIFA), and heteropoly acid has been developed.
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hypervalent iodine iii induced intramolecular cyclization reaction of substituted phenol ethers with an alkyl azido side chain a novel and efficient synthesis of quinone imine derivatives
ChemInform, 1999Co-Authors: Yasuyuki Kita, Masahiro Egi, Akiko Okajima, Makoto Ohtsubo, Takeshi Takada, Toyokazu Saiki, Hirofumi TohmaAbstract:Novel and efficient syntheses of quinone imine ketals (2a-j) and quinone imines (4a-h) from substituted phenol ethers (1a-k) bearing an alkyl azido side-chain using the combination of hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate) (PIFA) and trimethylsilyl trifuoromethanesulfonate (TMSOTf), have been developed.
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an unexpected intermolecular chiral biaryl coupling reaction induced by a hypervalent iodine iii reagent synthesis of potential precursor for ellagitannin
Chemical Communications, 1999Co-Authors: Mitsuhiro Arisawa, Hirofumi Tohma, Saori Utsumi, Makiko Nakajima, Namakkal G Ramesh, Yasuyuki KitaAbstract:A novel phenyliodine(III) bis(Trifluoroacetate) (PIFA)-induced intermolecular chiral biaryl coupling reaction has been accomplished using α-D-glucose derivatives as chiral templates.
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hypervalent iodine iii induced intramolecular cyclization of substituted phenol ethers bearing an alkyl azido sidechain a novel synthesis of quinone imine ketals
ChemInform, 1996Co-Authors: Yasuyuki Kita, Masahiro Egi, Akiko Okajima, Makoto Ohtsubo, Takeshi Takada, Hirofumi TohmaAbstract:A novel and efficient synthesis of quinone imine ketals from substituted phenol ethers bearing an alkyl azido sidechain using a hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate)(PIFA), is described.
Hirofumi Tohma - One of the best experts on this subject based on the ideXlab platform.
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a novel and efficient oxidative biaryl coupling reaction of phenol ether derivatives using a combination of hypervalent iodine iii reagent and heteropoly acid
Chemical Communications, 2002Co-Authors: Hiromi Hamamoto, Hirofumi Tohma, Gopinathan Anilkumar, Yasuyuki KitaAbstract:A novel and efficient oxidative biaryl coupling reaction of phenol ether derivatives using a combination of hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate) (PIFA), and heteropoly acid has been developed.
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hypervalent iodine iii induced intramolecular cyclization reaction of substituted phenol ethers with an alkyl azido side chain a novel and efficient synthesis of quinone imine derivatives
ChemInform, 1999Co-Authors: Yasuyuki Kita, Masahiro Egi, Akiko Okajima, Makoto Ohtsubo, Takeshi Takada, Toyokazu Saiki, Hirofumi TohmaAbstract:Novel and efficient syntheses of quinone imine ketals (2a-j) and quinone imines (4a-h) from substituted phenol ethers (1a-k) bearing an alkyl azido side-chain using the combination of hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate) (PIFA) and trimethylsilyl trifuoromethanesulfonate (TMSOTf), have been developed.
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an unexpected intermolecular chiral biaryl coupling reaction induced by a hypervalent iodine iii reagent synthesis of potential precursor for ellagitannin
Chemical Communications, 1999Co-Authors: Mitsuhiro Arisawa, Hirofumi Tohma, Saori Utsumi, Makiko Nakajima, Namakkal G Ramesh, Yasuyuki KitaAbstract:A novel phenyliodine(III) bis(Trifluoroacetate) (PIFA)-induced intermolecular chiral biaryl coupling reaction has been accomplished using α-D-glucose derivatives as chiral templates.
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hypervalent iodine iii induced intramolecular cyclization of substituted phenol ethers bearing an alkyl azido sidechain a novel synthesis of quinone imine ketals
ChemInform, 1996Co-Authors: Yasuyuki Kita, Masahiro Egi, Akiko Okajima, Makoto Ohtsubo, Takeshi Takada, Hirofumi TohmaAbstract:A novel and efficient synthesis of quinone imine ketals from substituted phenol ethers bearing an alkyl azido sidechain using a hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate)(PIFA), is described.
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a novel and direct alkyl azidation of p alkylanisoles using phenyl iodine iii bis Trifluoroacetate pifa and trimethylsilyl azide
Synlett, 1994Co-Authors: Yasuyuki Kita, Hirofumi Tohma, Takeshi Takada, Shizue Mitoh, Shigekazu Fujita, Michiyo GyotenAbstract:Treatment of p-alkylanisoles (1a-h) bearing benzylic protons with hypervalent iodine reagent, phenyliodine(III) bis(Trifluoroacetate) (PIFA) and trimethylsilyl azide (TMSN3) in acetonitrile gave arylalkyl azides (3a-h) in considerable yields.
A Yokozeki - One of the best experts on this subject based on the ideXlab platform.
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phase behavior of carbon dioxide in ionic liquids emim acetate emim Trifluoroacetate and emim acetate emim Trifluoroacetate mixtures
Journal of Chemical & Engineering Data, 2009Co-Authors: Mark B Shiflett, A YokozekiAbstract:The solubility (vapor−liquid equilibria) of carbon dioxide (CO2) has been measured in ionic liquids, 1-ethyl-3-methylimidazolium acetate ([emim][Ac]), 1-ethyl-3-methylimidazolium Trifluoroacetate ([emim][TFA]), and a mixture containing a fixed mole ratio of 49.98 ([emim][Ac])/50.02 ([emim][TFA]) using a gravimetric microbalance at three temperatures (298.1, 323.1, and 348.1) K and pressures up to about 2 MPa. The [emim][Ac] strongly (chemically) absorbed CO2 with hardly any vapor pressure above the mixture up to about 20 % mole fraction of CO2 at 298.1 K. The [emim][TFA] did not show the same behavior and physically absorbed CO2. The ionic liquid mixture containing equimolar amounts of [emim][Ac] and [emim][TFA] showed a combination of both chemical and physical effects, and the CO2 solubility was well predicted at a fixed pressure using either a molar average of the pure component solubilities or a model based on linear isobaric lines in the ternary phase diagram. The binary pressure−temperature (PTx) da...
Takeshi Takada - One of the best experts on this subject based on the ideXlab platform.
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hypervalent iodine iii induced intramolecular cyclization reaction of substituted phenol ethers with an alkyl azido side chain a novel and efficient synthesis of quinone imine derivatives
ChemInform, 1999Co-Authors: Yasuyuki Kita, Masahiro Egi, Akiko Okajima, Makoto Ohtsubo, Takeshi Takada, Toyokazu Saiki, Hirofumi TohmaAbstract:Novel and efficient syntheses of quinone imine ketals (2a-j) and quinone imines (4a-h) from substituted phenol ethers (1a-k) bearing an alkyl azido side-chain using the combination of hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate) (PIFA) and trimethylsilyl trifuoromethanesulfonate (TMSOTf), have been developed.
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hypervalent iodine iii induced intramolecular cyclization of substituted phenol ethers bearing an alkyl azido sidechain a novel synthesis of quinone imine ketals
ChemInform, 1996Co-Authors: Yasuyuki Kita, Masahiro Egi, Akiko Okajima, Makoto Ohtsubo, Takeshi Takada, Hirofumi TohmaAbstract:A novel and efficient synthesis of quinone imine ketals from substituted phenol ethers bearing an alkyl azido sidechain using a hypervalent iodine(III) reagent, phenyliodine(III) bis(Trifluoroacetate)(PIFA), is described.
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a novel and direct alkyl azidation of p alkylanisoles using phenyl iodine iii bis Trifluoroacetate pifa and trimethylsilyl azide
Synlett, 1994Co-Authors: Yasuyuki Kita, Hirofumi Tohma, Takeshi Takada, Shizue Mitoh, Shigekazu Fujita, Michiyo GyotenAbstract:Treatment of p-alkylanisoles (1a-h) bearing benzylic protons with hypervalent iodine reagent, phenyliodine(III) bis(Trifluoroacetate) (PIFA) and trimethylsilyl azide (TMSN3) in acetonitrile gave arylalkyl azides (3a-h) in considerable yields.
Abbas Rahmati - One of the best experts on this subject based on the ideXlab platform.
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a rapid and efficient method for the synthesis of 14h dibenzo α j xanthenes aryl 5h dibenzo b i xanthene 5 7 12 14 13h tetraone and 1 8 dioxo octahydroxanthenes by acidic ionic liquid
ChemInform, 2010Co-Authors: Abbas RahmatiAbstract:The clean synthesis is achieved using TFA as the catalyst in tetramethylguanidinium trifluoracetate ionic liquid.
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a rapid and efficient method for the synthesis of 14h dibenzo α j xanthenes aryl 5h dibenzo b i xanthene 5 7 12 14 13h tetraone and 1 8 dioxo octahydroxanthenes by acidic ionic liquid
Chinese Chemical Letters, 2010Co-Authors: Abbas RahmatiAbstract:Abstract Various xanthenes have been synthesized by the condensation of β -naphthol, 2-hydroxynaphthalene-1,4-dione or dimedone with various aldehydes in the presence of trifluoroacetic acid as catalyst in 1,1,3,3- N , N , N ′, N ′-tetramethylguanidinium Trifluoroacetate (TMGT) ionic liquid within 1 h at 75 °C.