Selective Amination of Polyhalopyridines Catalyzed by a Palladium−Xantphos Complex
作者:Jianguo Ji、Tao Li、William H. Bunnelle
DOI:10.1021/ol0357696
日期:2003.11.1
Amination of 5-bromo-2-chloropyridine (1a) catalyzed by a palladium-Xantphos complex predominately gives 5-amino-2-chloropyridine product 3a in 96% isolated yield and excellent chemoselectivity (3a/4a = 97:3). Amination of 2,5-dibromopyridine (11) under the same conditions exclusively affords 2-amino-5-bromopyridine 4a.
Selective Palladium-Catalyzed Aminations on 2-Chloro-3-iodo- and 2-Chloro-5-iodopyridine
作者:Bert U. Maes、Kristof T. Loones、Tim H. Jonckers、Guy L. Lemière、Roger A. Dommisse、Achiel Haemers
DOI:10.1055/s-2002-35579
日期:——
Regioselective palladium-catalyzed aminations with anilines on 2-chloro-3-iodo- and 2-chloro-5-iodopyridine have been performed with excellent yields and good selectivity. The use of a large excess of Cs2CO3 in combination with Pd-BINAP catalyst was essential to obtain sufficiently fast reactions. The mild conditions permit the presence of base sensitive functional groups. Moreover, the catalytic system developed also allows the arylamination of aryl iodides.