Copper(I)-Catalyzed Halogenation and Acyloxylation of Aryl Triflates through a Copper(I)/Copper(III) Catalytic Cycle
摘要:
Catalyzed by CuOTf under very mild conditions, aryl triflates which are embedded in the azacalix[1]-arene[3]pyridine macrocycle underwent coupling reactions with metal halides and acetates to afford respectively halogenated and acyloxylated arene products in moderate to excellent yields. The unprecedented CuOTf-catalyzed transformations of aryl triflates proceeded through an oxidative addition of intramolecularly chelated Cu(I) into the C-O bond of aryl triflates to form arylcopper(III) intermediates which underwent anion exchange and reductive elimination reactions with nucleophiles to yield functionalized macrocyclic products.
Cu(ClO<sub>4</sub>)<sub>2</sub>-Mediated Arene C–H Bond Halogenations of Azacalixaromatics Using Alkali Metal Halides as Halogen Sources
作者:Bo Yao、Zu-Li Wang、Hu Zhang、De-Xian Wang、Liang Zhao、Mei-Xiang Wang
DOI:10.1021/jo300152u
日期:2012.4.6
Regiospecific halogenation of azacalix[1]arene[3]pyridines at the lower rim position of the benzene ring was achieved from their cross-coupling reaction with cost-effective alkali metal halides through the Cu(ClO4)2-mediated aerobic aryl C–H activation, which gave structurally well-defined aryl-Cu(III) intermediates, and a subsequent C–X bond formation reaction under very mild conditions.