Tricyclohexylphosphine-cyclopalladated ferrocenylimine complexes: synthesis, crystal structures and application in Suzuki and Heck reactions.
A series of novel tricyclohexylphosphine (PCy(3))-cyclopalladated ferrocenylimine complexes 2c-2g have been easily synthesized. These new palladacycles are thermally stable and are not sensitive to air and moisture. Their detailed structures have been determined by single-crystal X-ray analysis and six different types of intermolecular hydrogen bonds are found to be existed in the crystals of these complexes. The use of 2c-2g as catalysts for Suzuki and Heck reactions was examined. They were found to be very efficient for the Suzuki reaction of aryl chlorides with phenylboronic acid. Typically, using 0.1 mol% of catalyst in the presence of 1.5 equivalent of Cs(2)CO(3) as base in dioxane at 100 degrees C provided coupled products in excellent yields. These complexes also displayed good activity in the Heck reaction of a range of aryl bromides with acrylic acid ethyl ester although they were not particularly useful for the activation of aryl chlorides.
Xu
Chen
C
Department of Chemistry, Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou, 450052, P R China.
Gong
Jun-Fang
JF
Yue
Su-Fang
SF
Zhu
Yu
Y
Wu
Yang-Jie
YJ
D002384:Catalysis; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D010720:Phosphines / Q000737:chemistry*
D007097:Imines; D010720:Phosphines