947769-95-1Relevant academic research and scientific papers
Bifunctional mesoporous silica nanoparticles as cooperative catalysts for the Tsuji-Trost reaction-tuning the reactivity of silica nanoparticles
Dickschat, Arne T.,Behrends, Frederik,Surmiak, Sabrina,Wei?, Mark,Eckert, Hellmut,Studer, Armido
, p. 2195 - 2197 (2013)
Bifunctional mesoporous silica nanoparticles (MSNs) bearing Pd-complexes and additional basic sites were prepared and tested as cooperative active catalysts in the Tsuji-Trost allylation of ethyl acetoacetate. Functionalization of the MSNs was realized by postmodification using click-chemistry. The selectivity of mono versus double allylation was achieved by control of reaction temperature and the nature of the catalyst.
Site-selective surface-initiated polymerization by Langmuir-Blodgett lithography
Brinks, Marion K.,Hirtz, Michael,Chi, Lifeng,Fuchs, Harald,Studer, Armido
, p. 5231 - 5233 (2007)
(Figure Presented) Brushing the surface: Structured polymer brushes are readily prepared by site-selective immobilization of initiators in a self-assembly process by Langmuir-Blodgett lithography with subsequent polymerization. The AFM images show a DPPC/
Palladium Nanoparticle Loaded Bifunctional Silica Hybrid Material: Preparation and Applications as Catalyst in Hydrogenation Reactions
Surmiak, Sabrina K.,Doerenkamp, Carsten,Selter, Philipp,Peterlechner, Martin,Sch?fer, Andreas H.,Eckert, Hellmut,Studer, Armido
, p. 6019 - 6028 (2017/05/05)
Bifunctional mesoporous silica was prepared by co-condensation of tetraethyl orthosilicate (TEOS) with functionalized organosilanes containing azides or alkoxyamines. Orthogonal functional groups at the particles were selectively addressed in subsequent chemical modifications through “click”-chemistry (“click to ligand” strategy) and radical nitroxide exchange. Palladation with PdCl2 delivered Pd nanoparticle-loaded silica material bearing sulfoxides and additional aminoamides as stabilizing ligands by means of in situ reduction of the PdII-salt. These functional particles were successfully applied to the hydrogenation of alkynes and alkenes. Aldehyde hydrodeoxygenation and benzyl ether cleavage were achieved with these hybrid catalysts under mild conditions. Particles were analyzed by IR, TEM/STEM, EDX, and solid-state NMR spectroscopy.
Pd immobilized in mesoporous silica particles as recyclable catalysts for suzuki-miyaura coupling: Cooperative effects exerted by co-immobilized amine functionalities
Dickschat, Arne T.,Surmiak, Sabrina,Studer, Armido
, p. 1523 - 1528 (2013/08/23)
A bifunctional heterogeneous palladium catalyst bearing additional basic sites was successfully prepared by sequential Cu-catalyzed 1,3-dipolar alkyne-azide cycloaddition and thermal nitroxide-exchange reaction of surface-bound alkoxyamines. This catalyst shows high activity in the Suzuki-Miyaura cross-coupling. The additional basic functionality acts cooperatively since an analogous heterogeneous Pd catalyst lacking the amine functionality is less active. Such catalysts can be recycled up to ten times without loss of activity. Georg Thieme Verlag Stuttgart. New York.
Preparation of bifunctional mesoporous silica nanoparticles by orthogonal click reactions and their application in cooperative catalysis
Dickschat, Arne T.,Behrends, Frederik,Bühner, Martin,Ren, Jinjun,Wei?, Mark,Eckert, Hellmut,Studer, Armido
, p. 16689 - 16697 (2013/03/14)
The synthesis of bifunctional mesoporous silica nanoparticles is described. Two chemically orthogonal functionalities are incorporated into mesoporous silica by co-condensation of tetraethoxysilane with two orthogonally functionalized triethoxyalkylsilanes. Post-functionalization is achieved by orthogonal surface chemistry. A thiol-ene reaction, Cu-catalyzed 1,3-dipolar alkyne/azide cycloaddition, and a radical nitroxide exchange reaction are used as orthogonal processes to install two functionalities at the surface that differ in reactivity. Preparation of mesoporous silica nanoparticles bearing acidic and basic sites by this approach is discussed. Particles are analyzed by solid state NMR spectroscopy, elemental analysis, infrared-spectroscopy, and scanning electron microscopy. As a first application, these particles are successfully used as cooperative catalysts in the Henry reaction. Cooperative clicking: Bifunctional mesoporous silica particles were synthesized by orthogonal surface chemistry. A thiol-ene reaction, a copper-catalyzed 1,3-dipolar cycloaddition and a radical nitroxide exchange reaction were used as orthogonal processes for the introduction of the acid and base functionalities (see scheme). Catalytic activities of these bifunctionalized inorganic/organic hybrid materials were studied on the Henry reaction. Copyright
