Nickel-catalyzed Heck reaction of cycloalkenes using aryl sulfonates and pivalates
作者:Jianrong Steve Zhou、Xiaolei Huang、Shenghan Teng、Yonggui Robin Chi
DOI:10.1039/d1cc00634g
日期:——
Nickel-catalyzed Heck reaction of cycloalkenes delivers unusual conjugated arylated isomers. Nickel(0) catalysts ligated by chelating dialkylphosphines effectively activate not only aryl triflates as electrophiles, but also less reactive aryl mesylates, tosylates and pivalates. The omission of bases allows nickel hydride species to exist long enough to perform in situ olefin isomerization of initial
Chemoselective Cross-Coupling between Two Different and Unactivated C(aryl)–O Bonds Enabled by Chromium Catalysis
作者:Jinghua Tang、Liu Leo Liu、Shangru Yang、Xuefeng Cong、Meiming Luo、Xiaoming Zeng
DOI:10.1021/jacs.0c00283
日期:2020.4.29
combination of low-cost Cr(II) salt, 4,4-di-tert-butyl-2,2-dipyridyl (dtbpy) ligand and magnesium reductant shows high reactivity in promoting the reductive cross-coupling of aryl methyl ether derivatives with aryl esters, by cleavage and coupling of two different C(aryl)-O bonds undermildconditions. The formation of active low-valent Cr species by reduction of CrCl2 with Mg can be considered, which prefers