Homogeneous and heterogeneous oligomerization reactions of olefins with unbridged metallocene catalysts

Endowing aspecific, unbridged-metallocene propylene-polymerization catalysts with isospecificity: the unprecedented role of MAO.

Observation of different catalytic activity of various 1-olefins during ethylene/1-olefin copolymerization with homogeneous metallocene catalysts.

This research aimed to investigate the copolymerization of ethylene and various 1-olefins. The comonomer lengths were varied from 1-hexene (1-C₆) up to 1-octadecene (1-C₁₈) in order to study the effect of comonomer chain length on the activity and properties of the polymer in the metallocene/MAO catalyst system. The results indicated that two distinct cases can be described for the effect of 1-...

Converting homogeneous to heterogeneous catalysts

Homogeneous transition metal complex catalysts for organic industrial processes are converted to catalysts which are heterogeneous with respect to the reactants, and which have substantially equal catalytic activity to the homogeneous catalysts. This is done by reacting a normally homogeneous transition metal complex catalyst with a metal bridging ligand which substantially duplicates the ligan...

Development of homogeneous and heterogeneous asymmetric catalysts for practical enantioselective reactions*

Two strategies for the development of practical asymmetric catalysis have been discussed in this article. The first part of this article focuses on the design and screening of highly efficient and enantioselective chiral catalysts for asymmetric hydrogenation reactions employing combinatorial approach. The second part presents a conceptually new strategy (i.e., “self-supporting” approach) for t...

Intelligent catalysts for ethylene oligomerization and polymerization

EEthylene polymerization catalysts became available in an enormous variety. The challenge in this research is to find catalysts that are able to connect ethylene molecules in such a way that not only linear chains are produced but variations like branched materials that possess very interesting mechanical properties like linear low density polyethylene (LLDPE). In this contribution, three diffe...

A Review on Heterogeneous Solid Catalysts and Related Catalytic Mechanisms for Epoxidation of Olefins with H2O2

The epoxidation reaction using heterogeneous solid catalysts with H2O2 as oxidants are environmentally friendly routes to produce extensively useful epoxides which are traditionally obtained from capital-intensive or environmentally polluted processes. In this paper, various types of solid catalysts for the epoxidation of olefins with H2O2 as oxidants are reviewed. The efficient catalysts repor...