Short Peptide-Derived Bifunctional Brønsted Base Catalysts in Asymmetric Michael Reactions/Peptido Laburretatik Eratorritako Brønsted Baseak Katalizatzaile Bifuntzional Moduan Michael Erreakzio Asimet
498 p.Peptide catalysis has proven to be an effective tool for the synthesis of
enantiomerically enriched compounds with synthetic applications or that are precursors
of molecules with biological and pharmacological interest. Their ability to interact
through H-bonds with the substrates and form complex H-bond networks is extremely
helpful for reaction stereocontrol. Likewise, asymmetric Brønsted base (BB) catalysis is
also a well stablished activation protocol for a great variety of transformations, and
especially interesting and effective are bifunctional BB catalysts bearing H-bond donors,
which can activate the nucleophile and the electrophile at the same time. In this context,
and in spite of the big progress in the realm of asymmetric catalysis, there are still many
new and challenging reactions that have not been resolved and/or require
improvement. So, the main goal of this Thesis has been to design and synthesize a new
family of catalysts that combine a short peptide, a typical privileged H-bond donating
scaffold used in organocatalysis (squaramide/ ureidoaminal) and a BB, and to
investigate them in some challenging transformations involving the generation of
quaternary carbon stereocenters.
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