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Supported catalysts manganese-porphyrin complexes

Key Words Polymer-supported catalysts, Manganese(ll) complexes, Manganese-salen complexes, Manganese-porphyrin complexes,... [Pg.388]

With respect to the widely investigated metalloporphyrins for catalytic epoxidation, progress was made in the area of polymer-supported ruthenium porphyrins for asymmetric epoxidation. Manganese-porphyrin complexes attached via peptide linkers to organic polymers showed enhanced selectivity and catalyst stability due to donor atoms in the linker that could coordinate to the metal center. This shows that improvement can be achieved not only by optimization of the polymer or metal complex but also by appropriate choice of the linker. Furthermore, electropolymerization by anodic oxidation of suitable manganese-porphyrin complexes proved to be a promising technique for the preparation of efficient immobilized epoxidation catalysts. [Pg.403]

Recently, Hulsken et al. have employed STM to probe the mechanism by which manganese porphyrin complexes achieve epoxidation of alkenes with dioxygen [69]. Importantly, this study demonstrates the positive role of solid-support immobilization in precluding the formation of inactive oxido-bridged catalyst dimers (a common deactivation pathway). [Pg.381]

Metal-catalysts that enable the direct transfer of an Ni-moiety from chloramine-T to alkenes with moderate efficiencies include metalloporphyrinoids. For example, in 2001, Simkhovich and Gross reported that iron (IV) corrole 21 (Scheme 2.29) catalyzed olefin aziridination with chloramine-T [44]. The use of porphyrine complexes of iron [Fe(TPP)Cl] and cobalt [Co(TDClPP)] in the presence of bromamine-T also allows for aziridinating a wide variety of alkenes [45,46]. A recyclable polymer-supported manganese (II) complex, which is readily prepared from chloromethy-lated poly(styrene-divinylbenzene) (PS-DVB) in two steps, transfers an Ni unit from bromamine-T to aliphatic alkenes in a heterogeneous system [47]. [Pg.78]

In the first topic - Fine Chemistry - the methodologies used in the het-erogenisation of manganese complexes into solid supports are briefly described. The major part of the section focuses on examples of heterogeneous manganese complexes with salen- and porphyrin-type ligands used as catalysts in the epoxidation of alkenes their catalytic activity is discussed as a... [Pg.281]


See other pages where Supported catalysts manganese-porphyrin complexes is mentioned: [Pg.61]    [Pg.63]    [Pg.223]    [Pg.873]    [Pg.389]    [Pg.395]    [Pg.279]    [Pg.495]    [Pg.810]    [Pg.207]    [Pg.295]    [Pg.409]    [Pg.529]    [Pg.307]    [Pg.761]   
See also in sourсe #XX -- [ Pg.395 ]




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Manganese catalysts

Manganese complexes

Manganese complexes catalysts

Manganese complexing

Manganese porphyrin catalyst

Manganese porphyrin complexes

Porphyrin complexes

Supported complexes

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