95957-93-0Relevant articles and documents
Lewis Acid-Catalyzed Selective Reductive Decarboxylative Pyridylation of N-Hydroxyphthalimide Esters: Synthesis of Congested Pyridine-Substituted Quaternary Carbons
Gao, Liuzhou,Wang, Guoqiang,Cao, Jia,Chen, Hui,Gu, Yuming,Liu, Xueting,Cheng, Xu,Ma, Jing,Li, Shuhua
, p. 10142 - 10151 (2019/10/16)
A practical and efficient Lewis acid-catalyzed radical-radical coupling reaction of N-hydroxyphthalimide esters and 4-cyanopyridines with inexpensive bis(pinacolato)diboron as reductant has been developed. With ZnCl2 as the catalyst, a wide range of quaternary 4-substituted pyridines, including highly congested diarylmethyl and triarylmethyl substituents, could be selectively obtained in moderate to good yields with broad functional group tolerance. Combined theoretical calculations and experimental studies indicate that the Lewis acid could coordinate with the cyano group of the pyridine-boryl radical to lower the activation barrier of the C-C coupling pathway, leading to the formation of 4-substituted pyridines. Moreover, it could also facilitate the decyanation/aromatization of the radical-radical coupling intermediate.
Palladium-catalyzed direct arylation of aryl(azaaryl)methanes with aryl halides providing triarylmethanes
Niwa, Takashi,Yorimitsu, Hideki,Oshima, Koichiro
, p. 2373 - 2375 (2008/02/05)
Direct arylation of aryl(azaaryl)methanes with aryl halidas takes place at the benzylic position in the presence of a hydroxide base under palladium catalysis to yield triarylmethanes
