Die Plant Science Student Conference (PSSC) wird seit 20 Jahren im jährlichen Wechsel von Studierenden der beiden Leibniz-Institute IPK und IPB organisiert. Im Interview erläutern Christina Wäsch (IPK) und Carolin Apel (IPB),…
Über 600 Gäste kamen am 4. Juli ans IPB zur Langen Nacht, die Wissen schafft, um bei unserem Wissenschafts-Quiz-Parcours viel Neues zu erfahren und ihre Kenntnisse unter Beweis zu stellen. Unser Programm in diesem Jahr…
Wessjohann, L. A.; Nin Brauer, M. C.; Brand, K.;Chalcogen-Based OrganocatalysisMahrwald, R., ed.209-314(2011)ISBN:978-90-481-3865-4DOI: 10.1007/978-90-481-3865-4_7
Most current organocatalysts are based on nitrogen (or phosphorus) as reactive atom, including also most processes depending on proton acidity and/or Lewis basicity. Only few organocatalytic systems use organochalcogens, although such reactions are of great importance in nature, especially evident in hydrolases with serine or cysteine as catalytic hotspot, or in oxidoreductases with cysteine or selenocysteine as key players. Catalytic processes in nature commonly rely on the nucleophilic or redox properties of chalcogen atoms. Accordingly early attempts in chemical catalysis using organochalcogens concentrate either on systems reminiscent of catalytic diads and triads of enzymes with catalysts consisting of a hydroxyl or sulfhydryl group that is activated as nucleophile by a neighboring base (catalytic diads and triads). Other “traditional” uses of chalcogen-based catalysts comprise chiral dioxiranes and oxaziranes for epoxidations, and sulfur redox catalysts, the latter especially in the application of sulfur ylides covered by the predominant work of Aggarwal et al. Since the advent of “Organocatalysis” as a distinct subfield of catalysis, not only these traditional organochalcogen catalyst systems excelled; also new applications are more systematically studied now, including not only oxygen and sulfur but increasingly selenium – and to a smaller extent – even tellurium based catalysis [372]. If nature and its several thousand years of selection of catalysis modes serve as a reference, group VI-based catalysis is yet very much below its real potential in chemical organocatalysis. This contribution thus aims at giving the reader an entry into this so much underutilized field, which offers ample room especially for those who like to try new paths and who not only wish expand on existing processes of well established nitrogen-based catalysts.