- Thermally Irreversible Photochromic Systems. Photoreaction of Diarylethene Derivatives with Imidazopyridine Rings
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A non-symmetrical diarylethene with imidazopyridine ring on one end and thiophene ring on the other end, 1,2-dicyano-1-(2-methylimidazopyridin-3-yl)-2-(2,4,5-trimethyl-3-thienyl)ethene 2Z underwent a hexatriene-cyclohexadiene type reversible ring-closure reaction by photoirradiation, while an only Z-E isomerization was observed for a symmetrical diarylethene with two imidazopyridine rings, 1,2-dicyano-1,2-bis(2-methylimidazopyridin-3-yl)ethene 1Z.The ring-closure reaction was not discerned.The photogenerated closed-ring form 2C had the absorption band at 535 nm, which is 23 nm longer wavelengths than that of the corresponding dithienylethene, and kept the absorption intensity constant for more than 24 h at 80 deg C.The quantum yield close to unity was observed for the photochemical ring-opening reaction of 2C with 546 nm light.
- Nakayama, Yasuhide,Hayashi, Koichiro,Irie, Masahiro
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- Synthesis of C3-Cyanomethylated Imidazo[1,2- a ]pyridines via Ultrasound-Promoted Three-Component Reaction under Catalyst- and Oxidant-Free Conditions
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An efficient synthesis of C3-cyanomethylated imidazo[1,2-α]pyridines via ultrasound-promoted three-component reaction under catalyst-free, oxidant-free, and mild conditions has been developed. A series of C3-cyanomethylated imidazo[1,2-α]pyridines were rapidly prepared with satisfactory yields and good functional group compatibility. This strategy cloud also be applied to the synthesis of zolpidem and alpidem in short steps.
- Wu, Qingguo,Yang, Haifeng,Zhang, Jian,Zhang, Jie,Zhang, Yufeng
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supporting information
p. 264 - 268
(2022/02/05)
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- A cyanogen methylation imidazopyridine compound of preparation method (by machine translation)
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The invention discloses a cyanogen methylation imidazopyridine compound of preparation method, in order to imidazo [1, 2 - a] pyridine compound as raw material, with the bromine second grade nitrile or [...] and under the action of the photocatalysis reaction, is obtained. Compared with the prior art, the method of the invention avoids the use of potassium cyanide or sodium cyanide and two connecting, iodomethane, and in the preparation of imidazo [1, 2 - a] pyridine compound of the cyanogen methylation product in the process, the chemical conversion from the original threestep shortened to step. The invention short preparation route, the preparation method is simple, the production cost is low, and the yield is high, have reduced the solvent to use and at the time of blowdown to the environment caused by pollution, easy to implement, easy to realize industrial. (by machine translation)
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Paragraph 0026; 0066; 0067
(2019/03/02)
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- Visible-Light-Induced Regioselective Cyanomethylation of Imidazopyridines and Its Application in Drug Synthesis
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3-Cyanomethylated imidazopyridines were synthesized via a visible light-promoted reaction of imidazopyridines with bromoacetonitrile or iodoacetonitrile catalyzed by fac-Ir(ppy)3 under mild conditions. For the substrates with various substituents on benzene or pyridine ring, the reaction proceeded smoothly to give the corresponding products in moderate to good yields. The synthetic utility of this visible-light-induced reaction has been illustrated in the efficient synthesis of zolpidem and alpidem.
- Chang, Qing,Liu, Zhengyi,Liu, Ping,Yu, Lu,Sun, Peipei
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p. 5391 - 5397
(2017/05/24)
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