- Regioselective Cyanation of Six-Membered N-Heteroaromatic Compounds Under Metal-, Activator-, Base- and Solvent-Free Conditions
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A regioselective cyanation of heteroaromatic N-oxides with trimethylsilyl cyanide has been developed to obtain 2-substituted N-heteroaromatic nitrile without the requirement of any external activator-, metal-, base-, and solvent. The present protocol is a straightforward, one-pot heteroaromatic C?H cyanation process, and proceeds smoothly in conventional heating but also under microwave irradiation with shorter reaction times. This approach now allows access to a broad class of quinoline N-oxides and other heteroarene N-oxides with high to good yields and can also be scaled up to obtain gram quantities. Further application of this process was observed and utilized in late-stage cyanation of the anti-malarial drug quinine as well as transformation of the 2-cyanoazines to a series of biologically important molecules. Based on the experimental observations, a plausible mechanism has also been proposed highlighting the dual role of trimethylsilyl cyanide as a nitrile source and as an activating agent. (Figure presented.).
- Sarmah, Bikash Kumar,Konwar, Monuranjan,Bhattacharyya, Dipanjan,Adhikari, Priyanka,Das, Animesh
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p. 5616 - 5625
(2019/11/22)
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- Regioselective direct oxidative C-H cyanation of quinoline and its derivatives catalyzed by vanadium-containing heteropoly acids
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A direct oxidative C-H cyanation of quinoline and its derivatives using trimethylsilyl cyanide as the cyano source and molecular oxygen as the terminal oxidant has been developed. In the presence of catalytic amounts of vanadium-containing heteropoly acids, e.g., H7PV4Mo8O40, cyanation of various quinoline and its derivatives preferentially took place at the 4-position, affording the corresponding substituted 4-cyanoquinolines as the major products.
- Yamaguchi, Kazuya,Xu, Ning,Jin, Xiongjie,Suzuki, Kosuke,Mizuno, Noritaka
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supporting information
p. 10034 - 10037
(2015/06/22)
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- Efficient formation of σH-adducts as a key step in the synthesis of acridines via Lewis acid-promoted transformations of the nitro group
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A step-by-step methodology was applied in the Lewis acid-promoted synthesis of fused heterocyclic systems from carbanions and nitroarenes. Efficient formation of σH-adducts of substituted nitrobenzenes and phenylacetonitrile derivatives followed by reductive transformation of the nitro group with silylating or acylating agents leads to 9-cyanoacridines. The method was found to be superior to the earlier one-pot approach, resulting in better yields and a broader scope of the reaction.
- Bobin, Mariusz,Kwast, Andrzej,Wróbel, Zbigniew
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p. 11048 - 11054
(2008/02/12)
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- Preparation of Heteroarenecarbonitriles by Reaction of Haloheteroarenes with Potassium Cyanide Catalyzed by Sodium p-Toluenesulfinate
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Several heteroarenecarbonitriles were prepared by reaction of haloheteroarenes with potassium cyanide catalyzed by sodium p-toluenesulfinate (1) or sodium methanesulfinate (2).In the reaction pathway, the cyanation proceeds through the formation of the su
- Miyashita, Akira,Suzuki, Yumiko,Ohta, Kiyono,Higashino, Takeo
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p. 345 - 356
(2007/10/02)
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- PREPARATION OF HETEROARENECARBONITRILES BY REACTION OF HETEROARENE N-OXIDES WITH TRIMETHYLSILYL CYANIDE IN THE PRESENCE OF DBU
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Several heteroarenecarbonitriles were prepared from the corresponding heteroarene N-oxides by treatment with trimethylsilylcyanide (TMSCN) in the presence of a base in tetrahydrofuran (THF). 1,8-Diazabicyclo-7-undecene (DBU) was found to be an effective base for the cyanation.
- Miyashita, Akira,Kawashima, Touru,Iijima, Chihoko,Higashino, Takeo
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p. 211 - 218
(2007/10/02)
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