Reactivity of<i>Para</i>-Substituted Fluorobenzenes in Palladium-catalyzed Intermolecular Direct Arylations
作者:Mian He、Jean-François Soulé、Henri Doucet
DOI:10.1002/cctc.201500185
日期:2015.7.13
C‐4 on fluorobenzene derivatives, for palladium‐catalyzed direct arylation at α‐position to the fluorine atom has been explored. With moderate electron‐withdrawing substituents, the reaction proceeds nicely using phosphine‐free PdCl2 catalyst, at a very low loading, and potassium pivalate/dimethylacetamide (PivOK/DMA) as catalytic system. In all cases, a regioselective arylation at the α position to
吸电子和供电子取代基(例如氨基,溴,氯,酮,甲基,甲氧基和硝基)在C-4上对氟苯衍生物的影响,用于钯催化氟原子上α位的直接芳基化已被探索。具有适度的吸电子取代基,使用无膦的PdCl 2催化剂,在非常低的负载量下,以新戊酸钾/二甲基乙酰胺(PivOK / DMA)作为催化体系,反应可顺利进行。在所有情况下,观察到在氟原子的α位置的区域选择性芳基化。此外,在芳基溴化物偶合伴侣上的各种取代基,例如甲酰基,硝基,腈,氯和甲基,以及杂芳基溴化物都是可以接受的。