Universität zu Köln

Köcher, Alicia Sabrina (2024). On the application of asymmetric transition metal catalyzed allylic substitutions: Studies on the total synthesis of the natural metastasis inhibitor camporidine A and synthesis of novel opines. PhD thesis, Universität zu Köln.

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Abstract

The present work deals with the synthesis of the piperidine alkaloid camporidine A, which was isolated from the gut bacteria of the ant species camponotus kiusiuensis. Due to its interesting 6/5/3 tricyclic structure and the discovered anti-metastatic activity, this natural product represents a challenging target molecule for organic synthesis. In particular, the focus was on the introduction of the stereocenters, which could be established by asymmetric Ir-catalyzed allylic substitutions. The central bicyclic system, which also appears in many camporidine-related structures, could be prepared by ring-closing metathesis, 1,3-dipolar cycloaddition of a nitrone intermediate and subsequent reductive cleavage of the N-O bond. Further functionalizations were also investigated using a test system. In addition, the synthesis of novel opines based on phenylalanine and tyrosine was investigated. With the help of an asymmetric Pd-catalyzed N-allylation and subsequent ozonolysis, the targeted opines could be produced in a highly stereoselective fashion in just a few steps. This way, reference compounds with known absolute configuration could be provided for the analytical assignment of opines in organisms.