SImCat · Imidazolidinethiones: Underexplored organocatalysts that show promise in catalyzing prebiotic and modern organic reactions
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-06-15 → 2023-04-14
- EU contribution
- €149,239
- Participants
- 1
- Scheme
- MSCA-IF
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Results in brief
Imidazolidinethiones: Underexplored organocatalysts that show promise in catalyzing prebiotic and modern organic reactions
Many chemical reactions are too slow to be productive and need catalysis to be more efficient. There are several methods to promote such intrinsically slow chemical reactions. Utilising so-called organocatalysts to boost chemical reactions provides an optimum of benefits, in particular when comparing the aspects of costs, energy efficiency, waste production, and negative environmental impacts to alternative methods such as heating and/or the use of metal-based catalysts. “Organo” in the word organocatalyst indicates that these molecules are comprised of chemical elements such as carbon, hydrogen, nitrogen, oxygen, and/or sulphur. The word part “catalyst” refers to the characteristic feature of these molecules, that is, that they enhance the rate of chemical transformations. Imidazolidine-4-thiones (ITO) are cyclic secondary amines and a class of organocatalysts, which have only been used in a few chemical transformations so far, possibly because they are not well understood. Importantly, imidazolidine-4-thiones may provide insight into the origins of life. This is because they can assemble from simple molecular building blocks that may have feasibly formed on the early Earth and could have catalysed prebiotic reactions that may have led to the generation of increasingly complex organic molecules on our planet. Therefore, it is of interest to garner a deeper understanding of imidazolidine-4-thiones and investigate their reactivity. This allowed us to better understand the role they played on the early Earth and gain insight on how to efficiently use them in reaction transformations.
Data: CORDIS, © European Union
Project objective
As elements in metal-based catalysis are becoming increasingly high risk, organocatalysts represent versatile, green, and robust catalysts as effective alternatives. Imidazolidine-4-thiones are 5-membered thioamide heterocycles with a secondary amine at ring position 1, which have structural similarity to imidazolidinones, successfully used as chiral organocatalysts. However, unlike imidazolidinones and proline-based catalysts, imidazolidinethiones are underexplored and underutilized as catalysts in organic reactions, their catalytic cycle is not proven, and the relative intermediates involved in the cycle have not been isolated to date. Earlier in 2020, imidazolidinethiones have been demonstrated by the Trapp group as suitable catalysts in the alkylation of aldehydes in prebiotic media, and they show promise as organocatalysts in modern organic reactions. In this project, I will investigate the reactivity of relevant intermediates in the organocatalytic cycle, that is, the enamines and iminium ions derived from the imidazolidinethiones and enolizable and non-enolizable aldehydes, respectively. The reactivity of imidazolidine-4-thione derived enamines and iminium ions will be quantified by kinetic measurements and results will embedded in the comprehensive Mayr reactivity scales. Experimental kinetic data will be acquired by applying photometric methods, which cover different timescales from conventional UV-vis spectroscopy to follow slow reactions via stopped-flow techniques to laser flash photolysis for reactions close to diffusion control, which proceed within nanoseconds. This fellowship will shed light on the unproven catalytic cycle and provide a quantitative basis for the future exploitation of this underutilized class of catalysts. Furthermore, I will develop skills in physical organic chemistry using quantitative structure-reactivity relationships and time resolved spectroscopy, while also refining soft skills such as leadership and teaching.
Original text from CORDIS.
Participants
- LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN · PlaneggCoordinatorGermany
Links
Data: CORDIS, © European Union