220105-73-7Relevant articles and documents
A facile and clean direct cyanation of heteroaromatic compounds using a recyclable hypervalent iodine(III) reagent
Dohi, Toshifumi,Morimoto, Koji,Takenaga, Naoko,Maruyama, Akinobu,Kita, Yasuyuki
, p. 1608 - 1610 (2006)
The facile and clean direct cyanating reaction of pyrroles and thiophenes has been achieved using a recyclable hypervalent iodine(III) reagent 1b by a simple solid-liquid separation of the products and the reagent.
Fluorination of pyrrole derivatives by Selectfluor
Heeran, Darren,Sandford, Graham
, p. 2456 - 2463 (2016/04/26)
Fluorination of a range of pyrrole substrates bearing various electron donating and withdrawing substituents at the 1-, 2- and 3-positons using Selectfluor has been assessed in order to develop effective methodology for the synthesis of corresponding fluo
Iron(II)-catalyzed direct cyanation of arenes with aryl(cyano)iodonium triflates
Shu, Zhibin,Ji, Wenzhi,Wang, Xi,Zhou, Yujing,Zhang, Yan,Wang, Jianbo
supporting information, p. 2186 - 2189 (2014/03/21)
A direct oxidative cyanation of arenes under FeII catalysis with 3,5-di(trifluoromethyl)phenyl(cyano)iodonium triflate (DFCT) as the cyanating agent has been developed. The reaction is applicable to wide range of aromatic substrates, including polycyclic structures and heteroaromatic compounds. Copyright
Practical synthesis of aromatic nitriles via gallium-catalysed electrophilic cyanation of aromatic C-H bonds
Okamoto, Kazuhiro,Watanabe, Masahito,Murai, Masahito,Hatano, Ryo,Ohe, Kouichi
supporting information; experimental part, p. 3127 - 3129 (2012/04/23)
A gallium-catalysed, direct cyanation reaction of aromatic and heteroaromatic C-H bonds with cyanogen bromide was developed as a practical synthetic method for the preparation of aromatic nitriles. The Royal Society of Chemistry 2012.
Hypervalent iodine(III): selective and efficient single-electron-transfer (SET) oxidizing agent
Dohi, Toshifumi,Ito, Motoki,Yamaoka, Nobutaka,Morimoto, Koji,Fujioka, Hiromichi,Kita, Yasuyuki
experimental part, p. 10797 - 10815 (2010/03/01)
In 1994, we first determined the single-electron-transfer (SET) oxidation ability of phenyliodine(III) bis(trifluoroacetate) (PIFA) toward phenyl ethers, affording the corresponding aromatic cation radicals. Since then, hypervalent iodine(III) has been utilized as a selective and efficient SET oxidizing agent 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, and indoles. The investigations and results obtained since the start of this century are summarized in this article.
Direct cyanation of heteroaromatic compounds mediated by hypervalent iodine(III) reagents: In situ generation of PhI(III)-CN species and their cyano transfer
Dohi, Toshifumi,Morimoto, Koji,Takenaga, Naoko,Goto, Akihiro,Maruyama, Akinobu,Kiyono, Yorito,Tohma, Hirofumi,Kita, Yasuyuki
, p. 109 - 116 (2007/10/03)
Hypervalent iodine(III) reagents mediate the direct cyanating reaction of a wide range of electron-rich heteroaromatic compounds such as pyrroles 1, thiophenes 3, and indoles 5 under mild conditions (ambient temperature), without the need for any prefunctionalization. Commercially available trimethylsilylcyanide is usable as a stable and effective cyanide source, and the reaction proceeds in a homogeneous system. The N-substituent of pyrroles is crucial to avoid the undesired oxidative bipyrrole coupling process, and thus a cyano group was introduced selectively at the 2-position of N-tosylpyrroles 1 in good yields using the combination of phenyliodine bis(trifluoroacetate) (PIFA), TMSCN, and BF3·Et2O at room temperature. In the reaction mechanism, cation radical intermediates of heteroaromatic compounds are involved as a result of single electron oxidation, and the key to successful transformations seems to depend on the oxidation potential of the substrates used. Thus, the reaction was also successfully extended to other heteroaromatic compounds having oxidation potentials similar to that of N-tosylpyrroles such as thiophenes 3 and indoles 5. However, regioisomeric mixtures of the products derived from the reaction at the 2- and 3-positions were obtained in the case of N-tosylindole 5a. Further investigation performed in our laboratory provided insights into the real active iodine(III) species during the reaction; the reaction is induced by an active hypervalent iodine(III) species having a cyano ligand in situ generated by ligand exchange reaction at the iodine(III) center between trifluoroacetoxy group in PIFA and TMSCN, and effective cyanide introduction into heteroaromatic compounds is achieved by means of the high cyano transfer ability of the hypervalent iodine(III)-cyano intermediates. In fact, the reaction of N-tosylpyrrole 1a with a hypervalent iodine(III)-cyano compound (e.g., (dicyano)iodobenzene 8), in the absence of TMSCN, took place to afford the 2-cyanated product 2a in good yield, and an effective preparation of the intermediates is of importance for successful transformation. 1,3,5,7-Tetrakis[4-{bis(trifluoroacetoxy)-iodo}phenyl]adamantane 12, a recyclable hypervalent iodine(III) reagent, was also comparable in the cyanating reactions as a valuable alternative to PIFA, affording a high yield of the heteroaromatic cyanide by facilitating isolation of the cyanated products with a simple workup. Accordingly, after preparing the active hypervalent iodine(III)-CN species by premixing of a recyclable reagent 12, TMSCN, and BF3· Et2U for 30 min in dichloromethane, reaction of a variety of pyrroles 1 and thiophenes 3 provided the desired cyanated products 2 and 4 in high yields. The iodine compound 13, recovered by filtration after replacement of the reaction solvent to MeOH, could be reused without any loss of activity (the oxidant 12 can be obtained nearly quantitatively by reoxidation of 13 using m-CPBA).
Novel and direct oxidative cyanation reactions of heteroaromatic compounds mediated by a hypervalent iodine(III) reagent
Dohi, Toshifumi,Morimoto, Koji,Kiyono, Yorito,Tohma, Hirofumi,Kita, Yasuyuki
, p. 537 - 540 (2007/10/03)
(Chemical Equation Presented) The hypervalent iodine(III) reagent phenyliodine bis(trifluoroacetate) (PIFA) mediates the selective cyanation reactions of a wide range of electron-rich heteroaromatic compounds such as pyrroles, thiophenes, and indoles unde
