New cyclic scaffolds under microflow and pressure conditions

Abstract

Polycyclic systems are the base structure to many pharmaceutical compounds with varying biological properties. The most straightforward reaction pathways to achieve these structures largely revolve around cyclisation, cycloaddition and, in some cases, annulation. There are different methods (high-pressure chemistry, thermochemistry, sonochemistry, microwave chemistry, electrochemistry, and photochemistry) to activate the reactions to obtain these compounds with each its advantages and drawbacks. Furthermore, a recurring need in organic chemistry is the production of complex compounds using methods with high atom-efficiency, reagentless and low cost.
In this context, cyclisation activated by UV-light is a simple method to obtain polycyclic compounds. Hence, in the first two chapters of this thesis, we examine the reactivity of different triplet aryl cations generated from (ortho-iodobenzyl)-β-tetralones, (ortho-iodobenzyl)indanones and tetrahydroquinolines. The results showed that products with either a phenanthrene and phenanthridine skeleton can be obtained in atom-efficient and reagentless conditions.
High-pressure is another activation method explored in the last two chapters. Its application to a Normal-Electron-Demand Diels-Alder reaction with various 5-nitroquinoline derivatives and electron-rich dienes, proved to be very efficient at giving 3D polycyclic products. Furthermore, the combination of high-pressure and a cyclic diene demonstrated that the diastereoselectivity of the Diels-Alder reaction can be controlled. A (4+2)/(3+2) domino reaction was also explored under hyperbaric conditions. The results from this multicomponent reaction showed that complex nitrosoaketal products could be achieved with ease and high atom-efficiency.

More information

Identifiers

ORCID for Marian Elise Powderly: orcid.org/0009-0009-3491-2124

ORCID for David Harrowven: orcid.org/0000-0001-6730-3573

Catalogue record

Export record