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Synthesis, Characterization and Catalytic Application of Aminodipyridylphosphine Oxide Palladium(II) Complex and Its Supported Form on Gold Nanoparticles. 日期: 2013.7.15 學生:陳盈源 指導教授:于淑君 博士. Types of Catalysts. Supported Catalysts. Concept :
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Synthesis, Characterization and Catalytic Application of Aminodipyridylphosphine Oxide Palladium(II) Complex and Its Supported Form on Gold Nanoparticles 日期:2013.7.15 學生:陳盈源 指導教授:于淑君 博士
Supported Catalysts • Concept: • Increasing the Heterogeniety of the Homogeneous Catalyst Systems. • Combining Both Benefits of Homogeneous and Heterogeneous Systems.
Hybrid Catalyst Design Gold nanoparticles (AuNPs) have been known not only to possess solid surfaces resembling the (1 1 1) surface of bulk gold but also to behave like soluble molecules for their dissolvability, precipitability, and redissolvability.
Spacing Linker Bidentate chelate effect Phosphine ligand • Phosphines are electronically and sterically tunable. • Air sensitive metal leaching • P-C, P-OR cleavage under high temperature. • Hazard waste • High cost
The Catalytic Applications of Palladium(II) • Advantages: • Functional group tolerance • Exhibit higher TOF • Suitably stable against water or air. Diverse Catalytic Reactivity: • Oxidation of Alcohols • Allylation of Aldehydes • Strecker Reaction • N-vinylation of amides • Heck • Stille • Suzuki • Sonogashira • Buchwald-Hartwig • Tsuji-Trost • Negishi • Oxidation of Alkenes
Motivation • To study the immobilization of molecular Pd(II) complexes on the surfaces of AuNPs by using the covalent linkage via a specially designed bipyridine ligand as spacing linkers. • Palladium catalyses have several advantages including functional group tolerance, exhibit higher TOF, and are suitably stable to run the reactions without the exclusion of water or air. • Using bipyridine ligand to replace phosphine ligand in organomatallic catalysis. • AuNPs have been known not only to possess solid surfaces resembling the (1 1 1) surface of bulk gold but also to behave like soluble molecules for their dissolvability, precipitability, and redissolvability.
Motivation • To design an easily recovered and effectively recycled AuNPs supported palladium(II) complex catalyst. • Because AuNPs are microwave conductor like bulk gold, we will apply microwave flash heating to replace conventional thermal heating.
IR Spectrum of HO-C11-Ppy2-Pd HO-C11-Ppy2 HO-C11-Ppy2-Pd Pd(OAc)2 1614 cm-1` Nagaki, A.; Takabayashi, N.; Moriwaki, Y.; Yoshida, J.-i. Chemistry – A European Journal2012, 18, 11871.
IR Spectrum of C4-Ppy2-Pd C4-Ppy2 C4-Ppy2-Pd Pd(OAc)2 1614 cm-1` Nagaki, A.; Takabayashi, N.; Moriwaki, Y.; Yoshida, J.-i. Chemistry – A European Journal2012, 18, 11871.
Crystal Structure of C4-Ppy2-Pd Pd 0.0461 Å N1 N2 O2 O4
Hostetler, M. J.; Templeton, A. C.; Murray, R. W. Langmuir1999, 15, 3782.
IR Spectrum of RS-Au-L-Pd RS-Au-L RS-Au-L-Pd
EDS and TEM Image of RS-Au-L-Pd 1.675 0.3164 nm
Recyclability of Catalyst RS-Au-L-Pd < 0.16 metal leaching
Mechanism of Enamide Formation Xu, J.; Fu, Y.; Xiao, B.; Gong, T.; Guo, Q., Tetrahedron Letters 2010,51 (41), 5476-5479.
Conclusions • We have developed a mild and efficient protocol for the Pd-catalyzed N-vinylation of amides with vinyl acetate. • The AuNPs supported Pd(II) complex catalyst not only provide comparable reactivity with its unbound form, but also offer excellent catalyst recyclability. • Further acceleration of the Pd(II) catalyzed N-vinylation was achieved under microwave irradiation conditions.
HO-C11-Ppy2-Pd HO-C11-Ppy2-Pd 65oC 2 hr