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Reference : UMR9168-GILFRI-001
Workplace : PARIS 05
Date of publication : Friday, May 15, 2020
Scientific Responsible name : Gilles Frison
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2020
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Multidisciplinary computational, synthetic and analytical approaches to reaction mechanism: the Hock reaction as a test case.
Continued technological and societal progress is based in part on the discovery of new molecules, new catalysts or new reactions that use less energy and are more environmentally friendly. These discoveries may be inspired by Nature or be based on hazard or on long and tedious experimental work based on the trial-and-error method. A more rational method to improve a reaction should focus on the detailed understanding of the chemical processes at the atomic scale.
The Hock rearrangement is an oxidative cleavage of allylic or benzylic hydroperoxides, which results in carbonyl products and it is now used in the industry to produce millions of tons of phenols (and the co-product acetone) each year, by the so-called cumene process. Another industrial application concerns the synthesis of artemisinin, a powerful drug used against malaria.
In this open PhD position funded by the French national research agency, we wish to expend the Hock reaction understanding and scope by a rational approach. The mechanism and selectivity of the Hock rearrangement, which has never been investigated so far, will be investigated. Furthermore, new methodology based on this reaction will be developed, in particular by interrupting the classical mechanism with an external nucleophile. A multidisciplinary approach, involving organic synthesis, computational chemistry and mass spectrometry, will be used to these aims. Model reagents will be synthesized and used to increase knowledge about the selectivity of the Hock reaction, the influence of Lewis acid catalysts or the nucleophile ability to trap the intermediate. Mass spectrometry analysis will be considered to study the stability, nature and possible isomerization of cationic reaction intermediates. Quantum chemistry (DFT methods) will be used to model the reaction paths. The comparison between theoretical and experimental data will allow to validate the theoretical approach and to envisage a predictive approach on the nature of the products for a given substrate before carrying out the synthesis.
This project is based on a collaboration between 2 laboratories:
- the LAboratoire de Chimie Théorique (LCT) of Sorbonne University located in Paris (5th arrondissement).
- the Laboratoire de Synthèse Organique (LSO) of Ecole polytechnique located in Palaiseau.
The research work will be carried out on these 2 sites, under the supervision of Gilles Frison (LCT) and Bastien Nay (LSO).
The student will be registered at the Doctoral School 388: Physical Chemistry and Analytical Chemistry of Sorbonne University.
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