81471-20-7Relevant articles and documents
NaBH4-TMEDA and a palladium catalyst as efficient regio- and chemoselective system for the hydrodehalogenation of halogenated heterocycles
Chelucci, Giorgio,Figus, Susanna
, p. 191 - 209 (2014/07/21)
The pair NaBH4-TMEDA as hydride source and a palladium catalyst in THF prove to be an efficient system for the hydrodehalogenation of halogenated heterocycles with one or more heteroatoms. In general, Pd(OAc) 2-PPh3 rapidly hydrodehalogenates reactive halo-heterocycles such as bromo-pyridines, -quinolines, -thiophenes, -indoles, -imidazoles, etc., at room temperature in very good yields, whereas in most cases PdCl2(dppf) reduces less reactive halides such as chloro-pyridines, -quinolines, -pyrimidines and bromo-indoles, -benzofurans, etc. Moreover, PdCl2(tbpf) shows to be even more active removing the 2- and 5-chlorine from both thiophene and thiazole rings. The reaction conditions tolerate various functional groups, allowing highly chemoselective reactions in the presence of halide, ester, alkyne, alkene and nitrile substituents. Moreover, with a proper selection of the catalyst it is also possible to obtain a good control in the regioselective hydrodehalogenation of a variety of polyhalogenated substrates.
Copper-mediated multiple C-H functionalization of aromatic N-heterocycles: Bromoamination of indoles and pyrroles
John, Alex,Nicholas, Kenneth M.
, p. 7914 - 7920 (2013/01/16)
A copper-mediated bromoamination of aromatic N-heterocycles has been achieved using oxime esters as the N-reagents under mild conditions (ca. 70 °C). The reaction with N-alkyl indoles proceeds regioselectively to produce the 2-amino-3-bromo indole derivatives as confirmed by X-ray crystallographic analysis of the bromoaminated product, 3aa-Br. With N-methylpyrrole both the monobromoaminated and dibromoaminated products were produced by this method.