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.
Intramolecular Nucleophilic Aromatic Substitution Reaction of 2-Carboxamido-3-arylquinazolin-4-ones and its Application to the Synthesis of Secondary Aryl Amines
A novel intramolecular nucleophilic aromatic substitution reaction of 2-carboxamido-3-arylquinazolin-4-one derivatives induced by base treatment and its application to the expeditious synthesis of secondary aryl amines, including diaryl amines, are described.
Study of a New Rate Increasing “Base Effect” in the Palladium-Catalyzed Amination of Aryl Iodides
作者:Caroline Meyers、Bert U. W. Maes、Kristof T. J. Loones、Gunther Bal、Guy L. F. Lemière、Roger A. Dommisse
DOI:10.1021/jo049774e
日期:2004.9.1
Evidence for an interphase deprotonation of Pd(II)-amine complexes with weak carbonate base has been gained for the first time. When a rate-limiting deprotonation step is involved in the catalytic cycle, controlling the structure (shape and size of the particles) and/or molar excess of the carbonate base used can significantly increase the reaction rate of Buchwald-Hartwig aminations. By taking such a "base effect" into account a general protocol for the intermolecular amination of aryl iodides with all types of amines has been developed based on a standard Pd-BINAP catalyst, using cesium carbonate as the base.