Research Paper (undergraduate) from the year 2019 in the subject
Chemistry - Bio-chemistry, grade: 1,0, University of Cologne, language:
English, abstract: This work is about the non-covalent catalysis and
concentrates on the hydrogen-bond catalysis. Nowadays it is common to
use catalysis in organic synthesis. It can help in orienting the
substrates, lowering barriers to reaction and accelerating the rates of
reaction. In addition to metal-ligand systems and biocatalysts, there is
another class of catalysts, the organocatalysts which are free of any
metals, like many enzymes. The organocatalysts often consist of chiral
compounds. The output materials are easy to find in the nature. How
these catalysts accelerate the reaction rates is a central question in
organic synthesis. It is important to distinguish the interactions with
the organic substrates between covalent and non-covalent bonds. The
activation of a carbonyl compound by conversion into an enamine or into
an iminium ion belongs to the covalent catalysis, while to increase the
electrophilicity of a carbonyl group by formation of hydrogen bondings
is a typical example for non-covalent organocatalysis. Thus, the
acceleration and the control of the reaction rates depend on formation
of hydrogen bonds for non-covalent organocatalysis. It is possible to
catalyse two hydrogen bonds which occur in dual hydrogen bonding donors.
