Metal-Free Oxidative Coupling Reactions via σ-Iodonium Intermediates: The Efficient Synthesis of Bithiophenes Using Hypervalent Iodine Reagents
作者:Koji Morimoto、Tomofumi Nakae、Nobutaka Yamaoka、Toshifumi Dohi、Yasuyuki Kita
DOI:10.1002/ejoc.201100969
日期:2011.11
The direct oxidative biaryl couplingreaction is an attractive tool for environmentally benign green chemistry. A novel direct method for the synthesis of bithiophene using a hypervalentiodinereagent has been developed. The reaction mechanism has also been investigated, casting light on the reaction intermediate and revealing the reactivity with iodonium salts.
Hypervalent iodine(III): selective and efficient single-electron-transfer (SET) oxidizing agent
作者:Toshifumi Dohi、Motoki Ito、Nobutaka Yamaoka、Koji Morimoto、Hiromichi Fujioka、Yasuyuki Kita
DOI:10.1016/j.tet.2009.10.040
日期:2009.12
ethers, affording the corresponding aromatic cation radicals. Since then, hypervalent iodine(III) has been utilized as a selective and efficient SET oxidizingagent that enables a variety of direct C–H functionalizations of aromatic rings in electron-rich arenes under mild conditions. We have now extended the original method to work in a series of heteroaromatic compounds such as thiophenes, pyrroles,
A novel and direct synthesis of alkylated 2,2′-bithiophene derivatives using a combination of hypervalent iodine(<scp>iii</scp>) reagent and BF<sub>3</sub><b>·</b>Et<sub>2</sub>O
作者:Hirofumi Tohma、Minako Iwata、Tomohiro Maegawa、Yorito Kiyono、Akinobu Maruyama、Yasuyuki Kita
DOI:10.1039/b302462h
日期:——
A novel nonmetallic oxidative coupling of alkylthiophene derivatives leading to the corresponding 2,2â²-bithiophene derivatives using a combination of a hypervalent iodine(III) reagent, phenyliodine bis(trifluoroacetate)
(PIFA), and BF3·Et2O was developed.
Synthesis of oligomeric 2,5-thienylenes; their u.v. spectra and oxidation potentials
作者:D. D. Cunningham、L. Laguren-Davidson、Harry B. Mark、Chiem Van Pham、Hans Zimmer
DOI:10.1039/c39870001021
日期:——
Oligomeric2,5-thienylenes and 3-methyl-2,5-thienylenes have been synthesized by NiCl2(dppp)(dppp = Ph2PCH2CH2CH2PPh2) coupling of Grignard compounds with the appropriate bromothiophene; u.v.spectra and oxidationpotentials of the oligomers are dicussed in terms of coplanarity of the oligomeric species.
Clean and Direct Synthesis of .ALPHA.,.ALPHA.'-Bithiophenes and Bipyrroles by Metal-Free Oxidative Coupling Using Recyclable Hypervalent Iodine(III) Reagents
作者:Toshifumi Dohi、Koji Morimoto、Chieko Ogawa、Hiromichi Fujioka、Yasuyuki Kita
DOI:10.1248/cpb.57.710
日期:——
The facile and clean oxidative biaryl coupling reaction of thiophenes and pyrroles has been achieved using the recyclable hypervalent iodine(III) reagents having adamantane or methane structures. These iodine(III) reagents could be recovered from the reaction mixtures by a simple solid-liquid separation, i.e., filtration.