Skip to main content
Go to the home page of the European Commission (opens in new window)
English en
CORDIS - EU research results
CORDIS

Total Syntheses of Catharanthine and Keramaphidin B by an Iridium-Catalyzed Reductive Cyclization Cascade

Project description

New potential route to catharanthine synthesis

The EU-funded CATKERB project plans to design a cascade cyclisation reaction for dihydropyridinones – an important subclass of heterocyclic compounds. The project's activities will be organised around finding suitable Lewis acids and better solvents, and optimising the reaction times and temperature. This reaction cascade provides a potential route to the late-stage synthesis of catharanthine. Catharanthine is a precursor of the anti-tumour drugs vinblastine and vincristine, formed by the dimerisation of catharanthine with vindoline. Vinblastine and vincristine are valuable agents in cancer treatment due to their ability to inhibit microtubule formation.

Objective

During the course of this Fellowship a reductive cyclization cascade for dihydropyridinones, which consists of an iridium-catalyzed reduction to the corresponding electron-rich dienes and subsequent [4+2] cycloaddition (Diels-Alder reaction) will be developed. A first promising proof of concept study establishing the feasibility of this powerful transformation has already been carried out in the Dixon group; however further optimization by varying the solvent, the reaction time, the temperature or by using suitable Lewis acids is required to perfect the methodology. The additional use of chiral Lewis acid or chiral amine catalysts is also intended to develop an enantioselective variant of this method. The methodology development should then be completed by determining the substrate scope. The resulting azabicyclo[2.2.2]octene motif is an important structural component of various alkaloids. Therefore, this reaction cascade should then be used as a late stage key step in the total syntheses of the natural products catharanthine and keramaphidin B.

Catharanthine is an important member of the large class of iboga alkaloids, which usually carry as common structural feature an indole or an indoline moiety. Catharanthine can be considered as a direct precursor of the dimeric Catharanthus alkaloids vinblastine and vincristine, both of which are clinically valuable agents in the treatment of cancer due to their ability to inhibit mitosis the formation of microtubules.

The marine alkaloid keramaphidin B belongs to the manzamine family and shows cytotoxicity against P388 leukaemia cells in mice (IC50 0.28 μg/mL) and against epidermal KB cancer cells in humans (IC50 0.30 μg/mL). Structurally, keramaphidin B is a pentacyclic compound comprising two piperidine rings (one bridged and one unbridged) and two macrocycles. Furthermore, this alkaloid has two (Z)-configured and one triple-substituted double bond, as well as four stereogenic centers, one of which is quaternary.

Fields of science (EuroSciVoc)

Programme(s)

Topic(s)

Funding Scheme

MSCA-IF-EF-ST - Standard EF

See all projects funded under this funding scheme

Call for proposal

(opens in new window) H2020-MSCA-IF-2019

See all projects funded under this call

Coordinator

THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD
Net EU contribution
€ 212 933,76
Address
WELLINGTON SQUARE UNIVERSITY OFFICES
OX1 2JD Oxford
United Kingdom
Region
South East (England) Berkshire, Buckinghamshire and Oxfordshire Oxfordshire
Activity type
Higher or Secondary Education Establishments
Links
Total cost
€ 212 933,76