Tetrafluoroborate
1-Chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate), with the formula C7H14B2ClF9N2, is a selective fluorine reagent which is white crystal at room temperature. It is mainly used asfluorinating agent to make single fluoridation with electronic double bond, silyl enol ether and enol lithium salt and so on. It can be used in the preparation of fluorinated steroid drugs, etc.
Reaction
1. It is one of the most efficient and popular reagents for electrophilic fluorination. The product is also useful as a reagent, or catalyst, for oxidative transformations, coupling reactions and halogenations.
2. Useful for the direct electrophilic fluorination of ketones, ketals and enamides.
3. Ritter-type C-H amination of unactivated sp3.
Main Usage
It is mainly used as fluorinating agent to make single fluoridation with electronic double bond, silyl enol ether and enol lithium salt and so on. It can be used in the preparation of fluorinated steroid drugs, etc.
Description
1-ChloroMethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)(Selectfluor) is a white solid (mp 190 °C), stable in air and to moisture. It is a dicationic salt soluble in cold water or dilute hydrochloric acid. However, it decomposes in dilute sodium hydroxide and reacts with cold DMSO (rapidly and exothermally) and with DMF (slowly on heating). It is moderately soluble in acetonitrile but only slightly soluble in lower alcohols and acetone, which makes the former the solvent of choice. Occasionally, reactions in these solvents were accelerated by adding a small amount of water or trifluoroacetic acid. Bulk quantities of Selectfluor should be stored in a cool, dry place and not heated above 80 °C. Fainzil’berg et al. have measured the reduction potentials of Selectfluor and other N-F compounds. With a positive reduction potential, E1/2 ) 0.33 V, Selectfluor is predicted to be a more reactive fluorinating reagent than, e.g., N-fluorobenzenesulfonimide, with E1/2 ) -1.24 V[1].
Chemical Properties
White powder
Uses
Effective electrophilic fluorinating reagent for a wide variety of substrates such as aromatics, alkenes, carbohydrates, etc.
Uses
Mild, versatile fluorinating reagent used in pharmaceutical and agricultural applications.
General Description
This product is a fluorine donor also called Selectfluor and has been enhanced for catalysis.
reaction suitability
reagent type: catalyst
reagent type: oxidant
reaction type: C-H Activation
Toxicology
1-ChloroMethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (F-TEDA-BF4) is moderately toxic (male rat oral LD50 640 mg kg1; female rat 350–500 mg kg1), and is an irritant to the eye and respiratory system. Always use approved dust mask (or respirator), gloves, and safety glasses when handling the solid. Carry out solubility tests on a sensible scale when seeking alternative solvents (note the problem with DMSO referred to above).
Advantages
As the advantages of non-toxicity, non-corrosion and chemical stability, 1-ChloroMethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) have been widely used in industry and public life.
References
[1] Rajendra P. Singh, Jean’ne M. Shreeve. “Recent Highlights in Electrophilic Fluorination with 1-Chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane Bis(tetrafluoroborate).” ChemInform 35 16 (2004).
![1-ChloroMethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) Structure](https://www.chemicalbook.com/CAS/GIF/140681-55-6.gif)
