(pyridines, pyrimidines, pyrazines, pyridazines, triazines, benzothiazoles, benzoxazoles, pyrazoles, benzindazoles, quinazolines, etc.) undergo smooth Pd-catalyzedcross-coupling reactions with functionalized aryl-, heteroaryl-, benzylic-, and alkylzinc reagents using Pd(OAc)2/S-Phos as the catalytic system mostly at 25 °C. No copper salt is required to perform these reactions.
Cobalt-Catalyzed Cross-Coupling Between In Situ Prepared Arylzinc Halides and 2-Chloropyrimidine or 2-Chloropyrazine
作者:Jeanne-Marie Bégouin、Corinne Gosmini
DOI:10.1021/jo900240d
日期:2009.4.17
A cobalt-catalyzed cross-coupling of aryl halides with 2-chloropyrimidines or 2-chloropyrazines is reported in satisfactory to high yields. The key step of this procedure is the formation of aromatic organozinc reagents and their coupling with 2-chlorodiazines using the same cobalt halide as catalyst and Zn dust under mild reaction conditions. This new cobalt-catalyzed coupling reaction represents a practical and interesting alternative to previously known methods for the synthesis of 2-aryldiazines.
Electrochemical cross-coupling between functionalized aryl halides and 2-chloropyrimidine or 2-chloropyrazine catalyzed by nickel 2,2′-bipyridine complex
2-Arylpyrimidines and 2-arylpyrazines have been obtained in good to high yields from 2-chloropyrimidine and 2-chloropyrazine and various functionalized aryl halides by electroreduction using an iron rod as the anode and a catalytic amount of nickel-bipyridine complex in a mixture of DMF and pyridine as solvent. (C) 1999 Elsevier Science Ltd. All rights reserved.