Organocatalysis, catalytic transformations with small organic molecules, has found
renewed interest in both academia and industry. Although it was already known for a
century that organic compounds could catalyze asymmetric reactions, it is only since half
a decade that the potential of organocatalysis is understood and is starting to be fully
explored. In the treatment of diseases, one enantiomer of a medicine is usually more
potent, and in the worst scenario, the opposite enantiomer can cause serious side effects
or even death. Therefore, the demand from both pharmaceutical and chemical industry
for new reliable asymmetric transformations of molecular skeletons is higher then ever.
Nowadays, the construction of (highly) functionalized asymmetric skeletons still suffers
from drawbacks, especially when there is a quaternary stereocenter involved in the target
molecule. Organocatalysis gained popularity in a relatively short time span, because it
has led to a large assortment of new asymmetric demanding transformations in the last
five years. In some cases, organocatalysts meet the selectivity and efficiency levels of
established metal catalyzed organic reactions. Since organocatalysis has a hidden
potential, it could provide a solution for challenging alterations in the future. Moreover,
organocatalysis can serve as a green alternative for transition metal catalyzed reactions.
During this master research project in organocatalysis we found that the organocatalyst βisocupreidine (β-ICPD) effectively catalyzes a one-step asymmetric transformation of
Morita-Baylis-Hillman carbonates. This transformation led to new molecular assemblies
with vicinal quaternary and tertiary stereocenters. We observed high chemo-, diastereo-,
and enantioselectivities with this reaction catalyzed by β-isocupreidine, in addition the
chemical yields of these transformations are excellent. This one-step organocatalytic
allylic alkylation is the first, out of six reactions reported, in which the reaction
mechanism can not be only explained in terms of a conjugate addition and thereby
leading to adjacent quaternary and tertiary stereocenters.