15032-21-0Relevant articles and documents
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Katritzky et al.
, p. 137 (1979)
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Small organic molecules with tailored structures: Initiators in the transition-metal-free C-H arylation of unactivated arenes
Chen, Suqing,Chen, Wenjun,Chen, Yu,Liu, Zhenghui,Mu, Tiancheng,Wang, Peng,Yan, Zhenzhong
, p. 14500 - 14509 (2020/04/27)
Simple, small organic molecules containing nitrogen and oxygen atoms in their structures have been disclosed to catalyze transition-metal-free C-H arylation of unactivated arenes with aryl iodides in the presence of tBuOK. In this article, an optimized catalytically active molecule, (2-(methylamino)phenyl)methanol, was designed. A broad range of aryl iodides could be converted into the corresponding arylated products at 100 °C over 24 h with good to excellent yields. Mechanistic experiments verified that radicals participated in this catalytic transformation and that the cleavage of the aromatic C-H bond was not the rate determining step. A K+ capture experiment by 18-crown-6 emphasized the significance of the cation species of the strong base. Fourier transform infrared spectroscopy proved that the catalytic system was activated by the hydrogen bonds between small organic molecules and tBuOK. Also, a clear mechanism was proposed. This transition-metal-free method affords a promising system for efficient and inexpensive synthesis of biaryls via a user-friendly approach, as confirmed by scale-up experiments.
Route to Highly Substituted Pyridines
Hilf, Justin A.,Holzwarth, Michael S.,Rychnovsky, Scott D.
, p. 10376 - 10382 (2016/11/17)
Pyridine rings are common structural motifs found in a number of biologically active compounds, including some top-selling pharmaceuticals. We have developed a new approach to access substituted pyridines. The method aims to provide a reliable synthesis of a diverse range of substituted pyridines through a three-step procedure. Readily available enones are first converted into 1,5-dicarbonyls through a two-step Hosomi-Sakurai allylation/oxidative cleavage sequence, which is followed by subsequent cyclization to the corresponding pyridine using hydroxylamine hydrochloride. A variety of substituted pyridines have been synthesized using this method.