Selective Csp³-F Bond Functionalization with Lithium Iodide.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• Carbon-fluorine (C-F) bond functionalization is crucial in organic synthesis.
• Developing efficient and selective methods for C-F bond activation remains a significant challenge.

Purpose of the Study:

• To present a novel, cost-effective method for the functionalization of aliphatic C-F bonds.
• To demonstrate the broad applicability of the method across various alkyl fluoride substrates.

Main Methods:

• Utilizing inexpensive lithium iodide as a key reagent for C-F bond activation.
• Employing a range of activated and unactivated primary, secondary, tertiary, benzylic, propargylic, and α-functionalized alkyl fluorides.
• Conducting reactions in chlorinated or aromatic solvents at room temperature or with mild heating.

Main Results:

• Achieved high yields (91-99%) for the conversion of alkyl fluorides to the corresponding iodides.
• Demonstrated selectivity for aliphatic monofluorides, with difluorides, trifluorides, and aryl fluorides remaining inert.
• Successfully coupled the C-F functionalization with *in situ* nucleophilic iodide replacements to form C-C, C-N, and C-S bonds with high yields.

Conclusions:

• The developed method offers an efficient and selective pathway for C-F bond functionalization of diverse aliphatic substrates.
• The reaction's compatibility with subsequent nucleophilic substitutions expands its synthetic utility.
• The use of inexpensive lithium iodide makes this a practical and scalable approach for organic synthesis.