Selectfluor

Selectfluor, a trademark of Air Products and Chemicals, is a reagent in chemistry that is used as a fluorine donor. This compound is a derivative of the nucleophillic base DABCO. It is a colourless salt that tolerates air and even water. It has been commercialized for use for electrophilic fluorination.

Selectfluor, a trademark of Air Products and Chemicals, is a reagent in chemistry that is used as a fluorine donor. This compound is a derivative of the nucleophillic base DABCO. It is a colourless salt that tolerates air and even water. It has been commercialized for use for electrophilic fluorination. ==Preparation== Selectfluor is synthesized by the N-alkylation of [[DABCO|diazabicyclo[2.2.2]octane (DABCO)]] with dichloromethane in a Menshutkin reaction, followed by ion exchange with sodium tetrafluoroborate (replacing the chloride counterion for the tetrafluoroborate). The resulting salt is treated with elemental fluorine and sodium tetrafluoroborate: The cation is often depicted with one skewed ethylene ((CH 2 ) 2 ) group. In fact, these pairs of CH 2 groups are eclipsed so that the cation has idealized C 3h symmetry. ==Mechanism of fluorination== Electrophilic fluorinating reagents could in principle operate by electron transfer pathways or an S N 2 attack at fluorine. This distinction has not been decided. By using a charge-spin separated probe, it was possible to show that the electrophilic fluorination of stilbenes with Selectfluor proceeds through an SET/fluorine atom transfer mechanism. In certain cases Selectfluor can transfer fluorine to alkyl radicals. ==Applications== The conventional source of "electrophilic fluorine", i.e. the equivalent to the superelectrophile F + , is gaseous fluorine, which requires specialised equipment for manipulation. Selectfluor reagent is a salt, the use of which requires only routine procedures. Like F 2 , the salt delivers the equivalent of F + . It is mainly used in the synthesis of organofluorine compounds: ===Specialized applications=== Selectfluor reagent also serves as a strong oxidant, a property that is useful in other reactions in organic chemistry. Oxidation of alcohols and phenols. As applied to electrophilic iodination, Selectfluor reagent activates the I–I bond in I 2 molecule. ==Related reagents== Similar to Selectfluor are N-fluorosulfonimides: ==References==

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