Palladium-catalyzed sonogashira and hiyama reactions using phosphine-free hydrazone ligands.
Palladium/copper-catalyzed Sonogashira cross-coupling reaction of aryl halides with a variety of terminal alkynes under amine-free conditions in dimethylformamide (DMF) at 80 degrees C gave internal arylated alkynes using PdCl2(MeCN)2 with phosphine-free hydrazone 2a as a ligand and CuI as the cocatalyst in good yields. We also found PdCl2/hydrazone ligand 1d in PhMe at 80 degrees C was a phosphine-free efficient catalyst system for a Hiyama cross-coupling reaction of aryl bromides with aryl(trialkoxy)silanes in good yields.
Mino
Takashi
T
Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. tmino@faculty.chiba-u.jp
Shirae
Yoshiaki
Y
Saito
Takeshi
T
Sakamoto
Masami
M
Fujita
Tsutomu
T