One-Pot Halogen Dance/Negishi Coupling of Dibromothiophenes for Regiocontrolled Synthesis of Multiply Arylated Thiophenes
作者:Kentaro Okano、Kazuhiro Sunahara、Yoshiki Yamane、Yuki Hayashi、Atsunori Mori
DOI:10.1002/chem.201604293
日期:2016.11.7
One‐pot halogen dance/Negishi cross‐coupling of readily available 2,5‐dibromothiophenes is described. A lithium diisopropylamide (LDA)‐mediated halogen dance reaction resulted in the formation of thermodynamically stable α‐lithiodibromothiophenes, which were transmetalated with ZnCl2 and subjected to Negishi cross‐coupling to provide the corresponding arylated dibromothiophenes in onepot. The resultant
NaBH4-TMEDA and a palladium catalyst as efficient regio- and chemoselective system for the hydrodehalogenation of halogenated heterocycles
作者:Giorgio Chelucci、Susanna Figus
DOI:10.1016/j.molcata.2014.06.012
日期:2014.11
Room-Temperature Hydrodehalogenation of Halogenated Heteropentalenes with One or Two Heteroatoms
作者:Giorgio Chelucci、Salvatore Baldino、Andrea Ruiu
DOI:10.1021/jo3019335
日期:2012.11.2
The pair NaBH4-TMEDA as a hydride source and catalytic PdCl2(4ppf) in THF prove to be an efficient system for the hydrodehalogenation of bromo(chloro)-heteropentalenes. with one or two heteroatoms, while Pd(OAc)(2)/PPh3 is able to reduce reactive haloheteropentalenes, and PdCl2(tbpf) allows the removal of the 2-chlorine from a thiophene ring. The reaction conditions tolerate various functional groups, allowing highly chemoselective reactions in the presence of halide, ester, alkyne, alkene, and nitrile substituents and also showing good efficiency in the regioselective hydrodehalogenation of a variety of polyhalogenated substrates.