Dept. of Biochemistry & Organic Chemistry
Lars Engman
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Organochalcogen chemistry & antioxidants
REsearch projects
Radicals in Organic Synthesis
In addition to metal mediated synthesis, free radical chemistry has emerged as one of the most powerful tools in modern organic synthesis and homolytic carbon carbon bond-formation is today routinely considered in retrosynthetic analysis. Radical reactions are intiated under mild conditions, they are often successful with substrates of vastly different polarity and they can be translated over a wide range of solvents. We are using readily available organoselenium and organotellurium compounds for radical cyclization and group transfer and carbonylation reactions.
Novel Antioxidants
Divalent organochalcogen compounds possess unique antioxidative properties. They react rapidly with hydroperoxides to form the corresponding oxides. Thus, they act as preventive, peroxide decomposing antioxidants. In addition, they can also readily undergo one-electron oxidation. This capacity make them excellent chain-breaking antioxidants. Furthermore, the ready reduction of the resulting tetravalent organochalcogens by many mild reducing agents set the scene for catalytic processes. We are presently involved in the design and synthesis of novel chalcogen-based catalytic antioxidants which could be used in biological systems and for the stabilisation of natural and synthetic materials such as polymers, oils and fluids, paper and pulp products etc.
Biologically Active Organoselenium and Organotellurium Compounds
Selenium is an essential trace element to man. Probably, more than thirty selenoenzymes are present in man. However, their structure and function are often poorly understood. We design and synthesize novel simple organoselenium and organotellurium compounds which could be expected to mimic some of the actions of these selenoenzymes or to have some other interesting biological activity. The biological effects of the compounds are evaluated in collaboration with biochemists, medicinal chemists and pharmaceutical companies.
