BIO PRE-ORGANOCATS · Biomimetic Multibinding Pre-Organocatalysts
FP7 — People (Marie Curie Actions)
- Duration
- 2013-10-01 → 2015-09-30
- EU contribution
- €50,000
- Participants
- 1
- Scheme
- MC-CIG
Lines connect the coordinator with its partners.
Results in brief
Biomimetic Multibinding Pre-Organocatalysts
The idea of this project was highly original and ambitious. In order to achieve the final scientific objectives, it was necessary to find a delicate reactivity balance between at least four different chemical entities in the same pot. During two years, different pre-organocatalysts have been synthesized and studied, but none of them has shown an advantageous reactivity compared to the standard aminocatalysts. Nevertheless, the study of the equilibria reactions of some of the reversible reactions of these substances has given key information to develop two new major advances using aminocatalysts. As usual in long term projects, the deviations of the main project occurred due to unexpected results. As a result of the mechanistic studies performed during this project, two main advances have been possible. The first one is the efficient chiral recognition of lactols and the second one, the discovery of a new really useful parameter to track the rate of the reactions. The new method for the chiral recognition of lactols is based on the knowledge derived from some of the studies performed during this project. In addition, this knowledge is of vital importance to understand the selectivity of all the aminocatalytic reactions where the distribution of downstream intermediates determines their selectivity. The new method allows the efficient differentiation of enantiomers of lactols in solution, which was impossible until now. This differentiation has already been used as the core of a new technology to separate gram quantities of important chiral lactols, that before could only be accessed from inefficient and expensive synthesis. During this project, we have also performed numerous studies on the effect of acids and bases on the equilibria involved in the addition of nucleophiles to conjugated aldehydes. We have discovered how sensitive all this equilibria are to the acidity of the media, but how difficult it is to control this parameter, especially when low concentrations of catalyst are used. A new parameter to correlate the rate of iminium activated aminocatalytic reactions has been developed. This new method is highly original and its use has allowed the reduction of the catalyst loading required to complete the reaction in a reasonable amount of time from typically 10-20 mol% to 0.1 mol%. In addition, in the context of this project, a new simple graphical kinetic analysis has been developed to determine the order of a reaction in catalyst. This new method has already been published in Angewandte Chemie International Edition and it will certainly be useful for many other researchers working in the catalysis area. The fellow has started his independent research career. He has got independent funding from other research funding agencies and industrial partners. He has participated actively in the teaching of the Chemistry Department at Imperial College London. It has been especially significant the creation of a new course of “Kinetics in Catalysis”, essential to tackle mechanistic studies successfully.
Data: CORDIS, © European Union
Project objective
Catalysis is an important field in chemistry because it allows to perform more environmentally and economically sustainable chemical processes. The end of the last century was dominated by the use of metal catalysts, which are expensive and pollutants. In the last decade, a new trend towards using small and relatively simple organic molecules as catalysts has witnessed incredible growth. These organocatalysts have become very popular but there are still several limitations related with their efficiency and selectivity that frustrate their incorporation to industrial processes. The massive screening approach undertaken until our days to solve these limitations has been proved inefficient, so a more rational approach seems necessary.In the last two years, deep mechanistic analyses performed by the coordinator of this proposal and others have shed light over the elements that control the reactivity and selectivity of organocatalytic reactions. The new mechanisms proposed have rationalized strange phenomena previously observed, have put an end to wrong preconceived ideas and have opened a new approach to organocatalysts design.This project intends to take advantage of the new catalytic downstream intermediates that will generate a Curtin–Hammett scenario. Under these conditions, the different thermodynamic stability of the intermediates will determine the reactivity and selectivity of the organocatalysts. This new design strategy is complementary to the classical one, which uses the different kinetic reactivity of a common intermediate as a determining factor.The multibinding organocatalysts will exploit the advantage of the Curtin–Hammett scenario and will benefit from catalytic downstream intermediates. In addition, the design proposed in this project has other advantages, such as the reduction of catalyst deactivation processes by using bio-inspired pre-organocatalysts and the possibility to easily create extensive multicomponent organocatalyst libraries.
Original text from CORDIS.
Participants
- IMPERIAL COLLEGE OF SCIENCE TECHNOLOGY AND MEDICINE · LondonCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union