CYCLO – Ag(II) promoted cycloaddition processes

Project Leader: Piotr Leszczyński, PhD DSc Project period: 2020 - 2023
Project funding: OPUS 18, NCN
Project description:

Hydrocarbons are simple organic compounds present in crude oil, which molecules are composed exclusively of carbon and hydrogen. One of most important challenges of modern chemical technology is the use and processing of light hydrocarbons in the industrial production of more complex organic compounds. Unsaturated hydrocarbons (alkenes, cycloalkenes and oligens), having carbon-carbon double bonds, being susceptible to the process of addition, i.e. coupling with other organic molecules, are mostly used in today’s chemical industry.

Due to the low reactivity of multiple bonds, the addition reactions of unsaturated hydrocarbons, proceed in multi-step processes involving the use of expensive catalysts to activate double bonds. Otherwise, such reactions would run with high difficulties or would not run at all. Continuous research regarding novel and effective ways of double bonds activation s very important, because the possibility of running industrial syntheses with direct use of crude oil components would significantly reduce production costs.

Numerous methods of double bonds activation are known, i.a. photochemical activation, chemical activation or electrochemical activation. Activation process considers oxidation of the double bond, which result in formation of highly reactive, short-living intermediate species (so called radical cations) able to attached to another, neutral organic molecule. In such way proceed cycloaddition reactions, including the Diels-Alder reactions, which are widely used in industry, e.g. in the synthesis of antiviral drugs.

CYCLO aims to design and explore a novel, previously unknown method of double bond activation in unsaturated hydrocarbon molecules, involving the use of an innovative activation agent containing divalent silver compounds, a very uncommon form of silver known to be one of the strongest chemical oxidants. Preliminary investigation have shown the ability of silver(II) compounds to activate double bonds in the molecules of light alkenes and cycloalkenes, which proves usefulness of silver(II) compounds as initiators of cycloaddition reactions, including Diels-Alder reactions.

CYCLO involves the use uncommon divalent silver compounds: silver(II) sulfate(VI) and its hydrate, which have been recently designed, obtained and pre-tested as reactants and activators in organic synthesis in our laboratory. Additionally, the possibility of using silver(II) compounds generated directly in the reaction system will be tested.

Cycloaddition reactions initiated by silver(II) compounds will be carried at room temperature, which is a big advantage of the new method. Determination reaction scenarios and identification of the products obtained will be carried out with use of standard analytical methods enabling separation of the products, determination of their chemical structure, and determination of the process’ efficiency and selectivity.

Systematic tests of reactivity of silver(II) compounds against various types of unsaturated organic compounds will be carried out to determine the “reactivity limit” of the process. Minimum load of silver(II) activator will be determined in a series of tests run with use of various concentrations of silver(II) compounds in the reaction mixture.

Understanding of the reactivity silver(II) compounds in the process of double bonds activation in the molecules of unsaturated hydrocarbons is important as a basic research task. Design of a new method of initiation of cycloadditions reactions would constitute a significant novelty, allowing further development of innovative synthesis technologies which could be used in industrial production of various chemicals of high market importance.

Realisation of the project is expected to result in design and validation of novel synthetic protocols of cycloaddition reactions activated by silver(II) compounds, which would allow to obtain complex products unavailable with use of other known methods.

Laboratory of Technology of Novel Functional Materials