Simona Pompei1, Christopher Grimm1, Judith E Farnberger2, Lukas Schober1, Wolfgang Kroutil1,3,4. 1. Institute of Chemistry NAWI Graz University of Graz Heinrichstrasse 28 8010 Graz Austria. 2. Austrian Centre of Industrial Biotechnology c/o Institute of Chemistry University of Graz Heinrichstrasse 28 8010 Graz Austria. 3. Field of Excellence BioHealth University of Graz 8010 Graz Austria. 4. BioTechMed Graz 8010 Graz Austria.
Abstract
Regioselective reactions represent a significant challenge for organic chemistry. Here the regioselective methylation of a single hydroxy group of 4-substituted catechols was investigated employing the cobalamin-dependent methyltransferase from Desulfitobacterium hafniense. Catechols substituted in position four were methylated either in meta- or para-position to the substituent depending whether the substituent was polar or apolar. While the biocatalytic cobalamin dependent methylation was meta-selective with 4-substituted catechols bearing hydrophilic groups, it was para-selective for hydrophobic substituents. Furthermore, the presence of water miscible co-solvents had a clear improving influence, whereby THF turned out to enable the formation of a single regioisomer in selected cases. Finally, it was found that also the pH led to an enhancement of regioselectivity for the cases investigated.
Regioselective reactions represent a significant challenge for organic chemistry. Here the regioselective methylation of a single hydroxy group of 4-substituted catechols was investigated employing the pan class="Chemical">cobalamin-dependent methyltransferase from Desulfitobacterium hafniense. Catechols substituted in position four were methylated either in meta- or para-position to the substituent depending whether the substituent was polar or apolar. While the biocatalytic cobalamin dependent methylation was meta-selective with 4-substituted catechols bearing hydrophilic groups, it was para-selective for hydrophobic substituents. Furthermore, the presence of water miscible co-solvents had a clear improving influence, whereby THF turned out to enable the formation of a single regioisomer in selected cases. Finally, it was found that also the pH led to an enhancement of regioselectivity for the cases investigated.
Authors: Robert C Simon; Barbara Grischek; Ferdinand Zepeck; Andreas Steinreiber; Ferdinand Belaj; Wolfgang Kroutil Journal: Angew Chem Int Ed Engl Date: 2012-05-22 Impact factor: 15.336
Authors: Silja Mordhorst; Jutta Siegrist; Michael Müller; Michael Richter; Jennifer N Andexer Journal: Angew Chem Int Ed Engl Date: 2017-02-07 Impact factor: 15.336