CUI Li-ping1, SONG Zi-wei1, XIE Yan-hong1, CHEN Xin2, LIU Pu1*
(1.Department of Chemistry, Zhengzhou University, Zhengzhou 45000, China; 2. Key Laboratory of Molecular Engineering of Polymers (Fudan University), Ministry of Education, Shanghai 200433, China )
Abstract: Dendritic poly(amidoamine)(PAMAM)-salicylidene salen palladium complex of the first generation (PAMAMSAPd) was synthesized and characterized by elemental analysis, FT-IR, UV-vis, Fluorescence spectra and NMR. It was evaluated as catalyst precursor in the Heck cross-coupling of iodobenzene (or its derivatives) and conjugate alkenes. For the cross-coupling reaction of iodobenzene with acrylic acid, the optimal condition was established as follows: 10mmol PhI, nPhI: nAA: nEt3N=1: 1.5: 2.5, 3.0×10-3g PAMAMSAPd, 4mL DMF and 100℃ reaction temperature in the inert ambience.Under the above reaction condition, the yield of cinnamate can reach 96.5% at 90min reaction time. This dendimer complex was a phosphine-free, highly efficient and stable dendrimer catalyst for Heck reaction. In addition, this dendrimer catalyst could be used at least for four times without significant loss of yield.
Keywords: Dendrimer, Palladium complex, Catalyst, Heck reaction
E-mail: liupu@zzu.edu.cn
Journal of Molecular Catalysis, Vol. 24, Issue 3, 2010, 247-253
