Partners and International Organizations
(English)
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A, B, HR, CZ, DK, F, D, H, IRL, I, LV, NL, N, PL, P, RO, SI, E, S, CH, GB
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Abstract
(English)
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Environmentally benign intermolecular radical addition reactions can be conducted using the Persistent Radical Effect (PRE). Alkoxyamines which are readily prepared from commercially available TEMPO (2,2,6,6-tertramethylpiperidin-1-oxyl radical) and dialkyl malonates are used as radical precursors. Malonyl radicals can be reversibly generated via thermal C-O-bond homolysis of these alkoxyamines. In the presence of olefins the malonyl radicals undergo addition to generate the corresponding adduct radicals which are subsequently trapped with TEMPO. Thus, the alkoxyamines undergo efficient thermal radical carboaminoxylations onto various nonactivated alkenes to provide 1,4-functionalized malonates in good to excellent yields. The experiments are very easy to conduct: simple mixing of the starting material and heating affords the desired functionalized malonates, which are useful compounds for further synthetic manipulations. The carboaminoxylations can be combined with radical cyclization and fragmentation processes. Furthermore, new 7- and 8-membered cyclic alkoxyamines, which are useful regulators/initiators for the living radical polymerization of styrene and n-butyl acrylate, have been developed during the last project period.
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