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The use of a new ZnO-supported palladium(0) nanoparticle catalyst for the cyanation of aryl halides using a relatively benign cyanide source, K4[Fe(CN)6], is described. This catalyst has been applied for the efficient cyanation of a variety of functionalized aryl bromides and activated aryl chlorides. This process circumvents the need for an additive and a(More)
Thiols and phosphines are the most widely used organic ligands to attain atomically precise metal nanoclusters (NCs). Here, we used simple hydrides (e.g., H-) as ligands along with phos-phines, such as triphenylphosphine (TPP), 1,2-bis(diphenylphosphino)ethane [DPPE], and tris(4-fluorophenyl)phosphine [TFPP] to design and synthesize a new class of(More)
A silica supported tetramethyl niobium complex [([triple bond, length as m-dash]SiO)NbMe4] 2 has been isolated by the surface alkylation of [([triple bond, length as m-dash]SiO-)NbCl3Me] 1 with dimethyl zinc in pentane. 1 can be easily synthesized by grafting NbCl3Me2 onto the surface of partially dehydroxylated silica by the SOMC strategy. Precise(More)
A well-defined, silica-supported bimetallic precatalyst [≡Si-O-W(Me)5≡Si-O-Zr(Np)3] (4) has been synthesized for the first time by successively grafting two organometallic complexes [W(Me)6 (1) followed by ZrNp4 (2)] on a single silica support. Surprisingly, multiple-quantum NMR characterization demonstrates that W and Zr species are in close proximity to(More)
The protection of the environment from toxic materials is an area of increasing concern. This review describes selected chemical processes that use more environmentally friendly solvents and less toxic catalysts. For example, water, ionic liquids and supercritical fluids have demonstrated promising activity as alternative benign reaction media for various(More)
The synthesis and full characterization of a well-defined silica-supported ≡Si-O-W(Me)5 species is reported. Under an inert atmosphere, it is a stable material at moderate temperature, whereas the homoleptic parent complex decomposes above -20 °C, demonstrating the stabilizing effect of immobilization of the molecular complex. Above 70 °C the grafted(More)
[WMe6 ] (1) supported on the surface of SiO2 -Al2 O3(500) (2) has been extensively characterized by solid-state NMR spectroscopy, elemental analysis, and gas quantification, which clearly reveal the formation of a mixture of monopodal and bipodal species with the migration of methyl from W to Al. The supported species SiO2 -Al2 O3(500) (2) transformed at(More)
The cross-coupling of allyl acetates and aryl and vinyl siloxanes proceeds readily by the catalysis of in situ generated palladium(0) nanoparticles. The reactions are stereoselective, and (E)-coupling products are obtained both from cis and trans allyl acetates. The coupling with vinyl siloxanes provides a novel protocol for the synthesis of 1,4-pentadienes.
Two compatible organometallic complexes, W(Me)6 (1) and TiNp4 (2), were successively anchored on a highly dehydroxylated single silica support (SiO2-700) to synthesize the well-defined bimetallic precatalyst [(≡Si-O-)W(Me)5(≡Si-O-)Ti(Np)3] (4). Precatalyst 4 was characterized at the molecular level using advanced surface organometallic chemistry (SOMC)(More)