Organic synthesis

Almost all projects in this research group require synthesis of new organic compounds (we buy anything that is commercially available). For example, synthesis of asphaltene model compounds is needed for our studies on the structures of the compounds in the heaviest fraction of crude oil, the asphaltenes. Further, synthesis of various saturated cyclic hydrocarbon model compounds is needed for the characterization of the chemical compositions of different fuels.

Scheme 1. Synthesis of an asphaltene model compound

Scheme 2. Synthesis of a saturated cyclic hydrocarbon model compound

Similarly, synthesis of tetrazene-type compounds and studies of their ions’ fragmentation patterns by using tandem mass spectrometry is important in our studies of the mechanisms of the burning of rocket fuels.

Scheme 3. Synthesis of a tetrazene derivative

Figure 22. Mass spectrum collected in a collision-induced dissociation experiment of a protonated tetrazene model compound (m/z 197) in an ion trap mass spectrometer. Proposed structures for each fragment ion are shown.

In addition, synthesis of several para-benzyne precursors allowed us to study the gas-phase reactivity of protonated para-benzynes, which is an important step towards the goal of developing antitumor drugs based on para-benzyne war heads.

Scheme 4. Synthesis of a para-benzyne precursor

Scheme 5. Gas-phase reactions between a charged para-benzyne and cyclohexane.²

Reference:

1. Sheng, H.; Ma, X.; Lei, H. R.; Milton, J.; Tang, W.; Jin, C.; Gao, J.; Wittrig, A. M.; Archibold, E. F.; Nash, J. J.; Kenttämaa, H. I. Polar Effects Control the Gas-Phase Reactivity of para-Benzyne Analogs. ChemPhysChem.2018, 19(21), 2839–2842.