1232006-42-6Relevant articles and documents
Photosolvolysis reactions of 3-alkoxypyridinium tetrafluoroborate salts
Penkett, Clive S.,Simpson, Iain D.
, p. 6183 - 6204 (1999)
Irradiation of a series of 3-alkoxypyridinium tetrafluoroborate salts in alcohol solution resulted in the formation of cyclopentenone ketals by diastereoselective incorporation of the alcohol solvent under the basic conditions of the photolysis reaction. In a second series of photochemical reactions, the same 3-alkoxypyridinium salts were irradiated in water to yield β-hydroxycyclopentanones stereoselectively.
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Metzler et al.
, p. 5377,5381 (1973)
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Taylor
, p. 1150,1155 (1951)
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Etherification of heterocyclic compounds by nucleophilic aromatic substitutions under green chemistry conditions
Lloung, Matthieu,Loupy, André,Marque, Sylvain,Petit, Alain
, p. 297 - 308 (2004)
Solid-liquid phase transfer catalysis coupled with microwave irradiation was shown to be an efficient method for SNAr reaction of halogenated quinoline and pyridine with alkoxides and phenoxides. Whereas for phenoxylation there is no need for any solvent, the addition of small amount of non-polar solvent is necessary during methoxylation for accurate monitoring of temperatures. Yields and conditions involved here constitute a noticeable improvement over classical methods within the frame of Green Chemistry. Specific MW effects were evidenced for phenoxylation and interpreted in terms of late position of the transition state along the reaction coordinates.
Visible-Light Promoted C–O Bond Formation with an Integrated Carbon Nitride–Nickel Heterogeneous Photocatalyst
Vijeta, Arjun,Casadevall, Carla,Roy, Souvik,Reisner, Erwin
supporting information, p. 8494 - 8499 (2021/03/08)
Ni-deposited mesoporous graphitic carbon nitride (Ni-mpg-CNx) is introduced as an inexpensive, robust, easily synthesizable and recyclable material that functions as an integrated dual photocatalytic system. This material overcomes the need of expensive photosensitizers, organic ligands and additives as well as limitations of catalyst deactivation in the existing photo/Ni dual catalytic cross-coupling reactions. The dual catalytic Ni-mpg-CNx is demonstrated for C–O coupling between aryl halides and aliphatic alcohols under mild condition. The reaction affords the ether product in good-to-excellent yields (60–92 %) with broad substrate scope, including heteroaryl and aryl halides bearing electron-withdrawing, -donating and neutral groups. The heterogeneous Ni-mpg-CNx can be easily recovered from the reaction mixture and reused over multiple cycles without loss of activity. The findings highlight exciting opportunities for dual catalysis promoted by a fully heterogeneous system.
Photorelease of Pyridines Using a Metal-Free Photoremovable Protecting Group
Dong, Zaizai,Fang, Xiaohong,Kou, Xiaolong,Tan, Weihong,Tang, Xiao-Jun,Wu, Yayun,Zhang, Zhen,Zhao, Rong,Zhou, Wei
supporting information, p. 18386 - 18389 (2020/08/24)
The photorelease of bioactive molecules has emerged as a valuable tool in biochemistry. Nevertheless, many important bioactive molecules, such as pyridine derivatives, cannot benefit from currently available organic photoremovable protecting groups (PPGs). We found that the inefficient photorelease of pyridines is attributed to intramolecular photoinduced electron transfer (PET) from PPGs to pyridinium ions. To alleviate PET, we rationally designed a strategy to drive the excited state of PPG from S1 to T1 with a heavy atom, and synthesized a new PPG by substitution of the H atom at the 3-position of 7-dietheylamino-coumarin-4-methyl (DEACM) with Br or I. This resulted in an improved photolytic efficiency of the pyridinium ion by hundreds-fold in aqueous solution. The PPG can be applied to various pyridine derivatives. The successful photorelease of a microtubule inhibitor, indibulin, in living cells was demonstrated for the potential application of this strategy in biochemical research.
Preparation method of cisapride key intermediate
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Paragraph 0026; 0027; 0032; 0033; 0038; 0039; 0044; 0045, (2019/01/06)
The invention provides a preparation method of a cisapride key intermediate. The preparation method includes the steps of adopting 3-pyridine as an initial raw material, 3-methoxypyridine is synthesized through nucleophilic substitution, 4-nitryl-3-methoxypyridine is prepared through a nitration reaction, a 4-nitryl-3-methoxyl-N-(3-(4-fluorophenoxy)propyl) quaternized pyridinium is prepared through quaternization, and the cisapride key intermediate, namely (cis)-N-(3-(4-fluorophenoxy)propyl)-4-amino-3-methoxy piperidine, is prepared through catalytic hydrogenation at last. The preparation method has the advantages of being low in cost, easy to operate and the like.
