The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Tadashi Okuyama - One of the best experts on this subject based on the ideXlab platform.
-
Vinyl Iodonium salts as precursors to vinyl cations
2020Co-Authors: Tadashi Okuyama, Morifumi FujitaAbstract:General reactivities of vinyl Iodonium salts are summarized, and reactions of cyclohexenyl, 1-alkenyl, styryl, and 2,2-disubstituted vinyl Iodonium salts are discussed in relation to possible formation of vinyl cation intermediates. Primary vinyl cation cannot be generated thermally but rearrangement via neighboring group participation often occurs. Photosolvolysis to give primary vinyl cation is also discussed.
-
Reactions of Cyclohexenyl Iodonium Tetrafluoroborate with Bromide Ion: Retardation Due to the Formation of λ3-Bromoiodane
Journal of Organic Chemistry, 2006Co-Authors: Tadashi Okuyama, Shohei Imamura, Morifumi FujitaAbstract:The reaction of 4-tert-butylcyclohex-1-enyl(phenyl)Iodonium tetrafluoroborate (1a) and the 4-chlorophenyl derivative (1b) with bromide ion was examined in methanol, acetonitrile, and chloroform. Products include those derived from the intermediate cyclohexenyl cation as well as 1-bromocyclohexene. Kinetic measurements show that the reaction of 1 is strongly retarded by the added bromide. The curved dependence of the observed rate constant on the bromide concentration is typical of a pre-equilibrium formation of the intermediate adduct with a fast bromide-independent reaction (solvolysis of the Iodonium ion). The formation of the adduct, λ3-bromoiodane, was also confirmed by the UV spectral change. The relative reactivity of the Iodonium ion and λ3-bromoiodane is evaluated to be on the order of 102. The bromide substitution product forms both via the SN1 reaction of the free Iodonium ion and via the ligand coupling of the iodane.
-
solvolysis of vinyl Iodonium salts new insights into vinyl cation intermediates
Accounts of Chemical Research, 2002Co-Authors: Tadashi OkuyamaAbstract:Solvolysis of some vinyl Iodonium salts carrying an excellent leaving group is examined, focusing on whether or not a classical primary vinyl cation can be generated. Formation of the primary cation is avoided, when possible, by participation of the β substituent in the heterolysis to form a vinylenebenzenium ion or a secondary vinyl cation. Definitive evidence against a primary vinyl cation is provided by a chirality probe approach in the solvolysis of 4-methylcyclohexylidenemethyl Iodonium salt.
N S Zefirov - One of the best experts on this subject based on the ideXlab platform.
-
hetaryl substituted phosphonium Iodonium ylides in synthesis of heterocycles
Journal of Organic Chemistry, 2012Co-Authors: E D Matveeva, Rolf Gleiter, T A Podrugina, Marina A Taranova, Ivanova M Anastasiya, N S ZefirovAbstract:A series of hitherto unknown hetaryl-substituted (in phosphonium part) phosphonium–Iodonium ylides were synthesized. The reaction of these mixed phosphonium–Iodonium ylides with acetylenes opens a way to new furyl annelated phosphinolines or unusually substituted phosphininofurans.
-
photochemical synthesis of phosphinolines from phosphonium Iodonium ylides
ChemInform, 2011Co-Authors: E D Matveeva, Rolf Gleiter, T A Podrugina, Marina A Taranova, A A Borisenko, Andrey V Mironov, N S ZefirovAbstract:Irradiation of phosphonium—Iodonium ylides with terminal alkynes results in formation of phosphinolines and/or 1,3-cycloaddition products depending on the nature of ylide and alkyne substituents.
-
one pot process in phosphonium Iodonium ylides nucleophilic substitution and the wittig reaction
Russian Chemical Bulletin, 2008Co-Authors: E D Matveeva, Andrei V. Mironov, A. S. Pavlova, T A Podrugina, N S ZefirovAbstract:The nucleophilic substitution in mixed phosphonium-Iodonium ylides was investigated. The Iodonium group is replaced by such S-containing nucleophiles as the thiocyanate anion or thiourea, as well as by halide ions. The structure of the reaction product with the thiocyanate ion was established by X-ray diffraction. A one-pot process involving the nucleophilic substitution and the Wittig reaction was developed.
Viktor V Zhdankin - One of the best experts on this subject based on the ideXlab platform.
-
oxidative cycloaddition of aldoximes with maleimides using catalytic hydroxy aryl Iodonium species
Advanced Synthesis & Catalysis, 2016Co-Authors: Akira Yoshimura, Mekhman S Yusubov, Khiem C Nguyen, Gregory T Rohde, Akio Saito, Viktor V ZhdankinAbstract:A mild catalytic procedure for the efficient oxidative cyclization of aldoximes with maleimides mediated by hypervalent iodine(III) active species has been developed. This catalytic cyclization affords the corresponding pyrrolo-isoxazole products in generally good yields. The catalytic cycle involves active hydroxy(aryl)Iodonium species generated in situ from 2-iodobenzoic acid as precatalyst and m-chloroperoxybenzoic acid (m-CPBA) as terminal oxidant in the presence of trifluoromethanesulfonic acid. The presence of active hydroxy(aryl)Iodonium species in this reaction has been confirmed by ESI-mass spectrometry and 1H NMR spectroscopy.
-
Applications of Iodonium salts and Iodonium ylides as precursors for nucleophilic fluorination in Positron Emission Tomography
Arkivoc, 2013Co-Authors: Mekhman S Yusubov, Dmitrii Yu. Svitich, Mariia S. Larkina, Viktor V ZhdankinAbstract:This review summarizes the applications of Iodonium compounds in the rapidly developing field of Positron Emission Tomography (PET). Reactions of diarylIodonium salts with fluoride anion have found wide practical application in PET as a fast and convenient method for the introduction of the radioactive ( 18 F)-fluoride into radiotracer molecules. The best synthetic methods for the preparation of Iodonium precursors for PET are described, the mechanistic aspects of nucleophilic fluorination reaction are discussed, and specific examples of the preparation of PET radioligands are provided.
-
new highly soluble dimedone derived Iodonium ylides preparation x ray structure and reaction with carbodiimide leading to oxazole derivatives
ChemInform, 2013Co-Authors: Akira Yoshimura, Pavlo V Solntsev, Lei Ji, Victor N Nemykin, Viktor V ZhdankinAbstract:The synthesis of new Iodonium ylides derived from dimedone and bearing an ortho-substituent in the phenyl ring is described.
-
Iodonium salts in organic synthesis
Arkivoc, 2011Co-Authors: Mekhman S Yusubov, Andrey V Maskaev, Viktor V ZhdankinAbstract:This review summarizes the chemistry of Iodonium salts with emphasis of their synthetic applications. The preparation and reactions of diarylIodonium, alkenyl(aryl)Iodonium, alkynyl(aryl)Iodonium, and alkyl(aryl)Iodonium salts are overviewed. Application of these reagents allows mild and highly selective arylations, alkenylations, alkynylations, and alkylations of various organic and inorganic substrates in a facile and environmentally friendly manner.
-
A general approach to aryl(cyano)Iodonium triflates - versatile Iodonium transfer reagents
Tetrahedron Letters, 1993Co-Authors: Viktor V Zhdankin, Michael C. Scheuller, Peter J. StangAbstract:Aryl(cyano)Iodonium triflates (ArI+CN −OTf, Ar = Ph, 4-CF3C6H4, 3,5-(CF3)2C6H3, 4-FC6H4) can be prepared in two steps from the corresponding aryliodides by oxidation with pertrifluoroacetic acid and subsequent reaction with Me3SiOTf and Me3SiCN. These compounds react with tributyltin derivatives of acetylenes, aromatic or heteroaromatic compounds under mild conditions forming the corresponding Iodonium salts 5, 7, 9 in good yield.
E D Matveeva - One of the best experts on this subject based on the ideXlab platform.
-
hetaryl substituted phosphonium Iodonium ylides in synthesis of heterocycles
Journal of Organic Chemistry, 2012Co-Authors: E D Matveeva, Rolf Gleiter, T A Podrugina, Marina A Taranova, Ivanova M Anastasiya, N S ZefirovAbstract:A series of hitherto unknown hetaryl-substituted (in phosphonium part) phosphonium–Iodonium ylides were synthesized. The reaction of these mixed phosphonium–Iodonium ylides with acetylenes opens a way to new furyl annelated phosphinolines or unusually substituted phosphininofurans.
-
photochemical synthesis of phosphinolines from phosphonium Iodonium ylides
ChemInform, 2011Co-Authors: E D Matveeva, Rolf Gleiter, T A Podrugina, Marina A Taranova, A A Borisenko, Andrey V Mironov, N S ZefirovAbstract:Irradiation of phosphonium—Iodonium ylides with terminal alkynes results in formation of phosphinolines and/or 1,3-cycloaddition products depending on the nature of ylide and alkyne substituents.
-
one pot process in phosphonium Iodonium ylides nucleophilic substitution and the wittig reaction
Russian Chemical Bulletin, 2008Co-Authors: E D Matveeva, Andrei V. Mironov, A. S. Pavlova, T A Podrugina, N S ZefirovAbstract:The nucleophilic substitution in mixed phosphonium-Iodonium ylides was investigated. The Iodonium group is replaced by such S-containing nucleophiles as the thiocyanate anion or thiourea, as well as by halide ions. The structure of the reaction product with the thiocyanate ion was established by X-ray diffraction. A one-pot process involving the nucleophilic substitution and the Wittig reaction was developed.
Rolf Gleiter - One of the best experts on this subject based on the ideXlab platform.
-
Mixed Iodonium-, phosphonium-, arsonium-, sulfoniumdiazonium ylides in reactions with nucleophiles
Russian Chemical Bulletin, 2019Co-Authors: Tatyana A. Podrugina, Andrei V. Mironov, A. S. Pavlova, D. S. Vinogradov, M. V. Shuvalov, I. D. Potapov, I. I. Levina, Rolf GleiterAbstract:The reactions of mixed ylides containing a diazonium fragment and an "onium" group of different nature with nucleophiles were studied. In the Iodonium-diazonium and sulfoniumdiazonium ylide, the nucleophile first of all substitutes the Iodonium and sulfonium group. A series of hetaryl-substituted phosphazines was obtained by a one-pot process of nucleophilic substitution in a diazonium-Iodonium ylide with subsequent nucleophilic addition of triarylphosphine at the diazo group.
-
Mixed arsonium–Iodonium and sulfonium–Iodonium ylides: synthesis and characteristics
Tetrahedron, 2016Co-Authors: Tatyana A. Podrugina, Vera A. Alferova, Andrei V. Mironov, Elena D. Matveeva, Rolf Gleiter, Nikolay S. ZefirovAbstract:Abstract The preparation and properties of novel mixed arsonium–Iodonium and sulfonium–Iodonium ylides are reported. A series of substituted arsonium and sulfonium ylides was obtained by the nucleophilic substitution of Iodonium groups in mixed ylides. A one-pot process, which included the nucleophilic substitution and silylation of arsonium–Iodonium ylides with subsequent elimination of the silyl group and a Wittig olefination reaction, provided route to access Z-α,β-unsaturated haloketones.
-
hetaryl substituted phosphonium Iodonium ylides in synthesis of heterocycles
Journal of Organic Chemistry, 2012Co-Authors: E D Matveeva, Rolf Gleiter, T A Podrugina, Marina A Taranova, Ivanova M Anastasiya, N S ZefirovAbstract:A series of hitherto unknown hetaryl-substituted (in phosphonium part) phosphonium–Iodonium ylides were synthesized. The reaction of these mixed phosphonium–Iodonium ylides with acetylenes opens a way to new furyl annelated phosphinolines or unusually substituted phosphininofurans.
-
photochemical synthesis of phosphinolines from phosphonium Iodonium ylides
ChemInform, 2011Co-Authors: E D Matveeva, Rolf Gleiter, T A Podrugina, Marina A Taranova, A A Borisenko, Andrey V Mironov, N S ZefirovAbstract:Irradiation of phosphonium—Iodonium ylides with terminal alkynes results in formation of phosphinolines and/or 1,3-cycloaddition products depending on the nature of ylide and alkyne substituents.
