372-47-4Relevant articles and documents
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Beaty,Musgrave
, p. 875,878 (1952)
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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.
Mild fluorination of chloropyridines with in situ generated anhydrous tetrabutylammonium fluoride
Allen, Laura J.,Muhuhi, Joseck M.,Bland, Douglas C.,Merzel, Rachel,Sanford, Melanie S.
, p. 5827 - 5833 (2014/07/08)
This paper describes the fluorination of nitrogen heterocycles using anhydrous NBu4F. Quinoline derivatives as well as a number of 3- and 5-substituted pyridines undergo high-yielding fluorination at room temperature using this reagent. These results with anhydrous NBu4F compare favorably to traditional halex fluorinations using alkali metal fluorides, which generally require temperatures of ≥100 °C.
An improved catalyst system for the Pd-catalyzed fluorination of (hetero)aryl triflates
Lee, Hong Geun,Milner, Phillip J.,Buchwald, Stephen L.
, p. 5602 - 5605 (2013/11/19)
The stable Pd(0) species [(1,5-cyclooctadiene)(L·Pd)2] (L = AdBrettPhos) has been prepared and successfully evaluated as a precatalyst for the fluorination of aryl triflates derived from biologically active and heteroaryl phenols, challenging substrates for our previously reported catalyst system. Additionally, this precatalyst activates at room temperature under neutral conditions, generates 1,5-cyclooctadiene as the only byproduct, and leads to overall cleaner reaction profiles.
