A structural study of seven N-acylindolines and their Pd(II)-mediated intramolecular oxidative coupling reactions for the synthesis of pyrrolophenanthridone alkaloids
Abstract
Direct synthesis of the pyrrolophenanthridone scaffold was explored using an intramolecular Pd(II)-mediated coupling reaction of different N-acylindolines via Csbnd H activation. Amaryllidaceae alkaloids of the lycorine type belong to this type. Depending on the substitution pattern of the starting materials, the pathway yielded different product patterns and yields. Introduction of electron-withdrawing substituents into the 6-position of the indoline moiety did not improve coupling. Seven N-acylindoline precursors were structurally characterized by X-ray crystallography and NMR spectroscopy. The crystal structure of the lycorine type alkaloid oxoassoanine is reported for the first time.
- Publication:
-
Journal of Molecular Structure
- Pub Date:
- February 2019
- DOI:
- 10.1016/j.molstruc.2018.10.031
- Bibcode:
- 2019JMoSt1178..341F
- Keywords:
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- Oxoassoanine;
- N-Acylindoline;
- Phenanthridone;
- Palladium;
- Crystal structure