Synthesis of Cyclic Ethers with Fluorinated Side Chains.

Area of Science:

• Organic Chemistry
• Fluorine Chemistry
• Free Radical Reactions

Background:

• Free radical addition reactions are crucial for synthesizing functionalized organic molecules.
• Fluorinated alkenes offer unique reactivity due to the electron-withdrawing nature of fluorine atoms.
• Tetrahydrofuran (THF) and dioxane are common cyclic ethers used as solvents and reagents.

Purpose of the Study:

• To investigate the free radical addition of THF and dioxane to various fluorinated alkenes.
• To determine the influence of alkene structure on the regioselectivity (unidirectional vs. bidirectional) of the addition.
• To synthesize novel polyfluorinated ethers and their metal complexes.

Main Methods:

• Di-tert-butyl peroxide initiated free radical addition reactions.
• Controlled molar ratios of reactants (THF, dioxane, fluorinated alkenes, 18-crown-6) to achieve specific substitution patterns.
• Characterization of products using spectroscopic methods and X-ray crystallography for selected complexes.

Main Results:

• Successful synthesis of various mono- and di-substituted fluorinated ethers via THF and dioxane addition.
• Regioselectivity of the addition was found to depend on the fluorinated alkene's structure.
• Formation of polyfluorinated 18-crown-6 derivatives and their lanthanum complexes, including novel fluorinated lanthanum triflate complexes.

Conclusions:

• The free radical addition of cyclic ethers to fluorinated alkenes provides a versatile route to complex fluorinated molecules.
• The study demonstrates tunable synthesis of substituted ethers and crown ethers by controlling reaction stoichiometry.
• The characterized lanthanum complexes highlight potential applications in catalysis or materials science.