Дифтортрифенилфосфоран

Description

Difluorotriphenylphosphorane (F2TPhP) is a hypervalent fluorophosphorane compound, a pentacoordinate derivative of triphenylphosphine with two fluoride ligands on the phosphorus(V) atom. According to the product heading it belongs to phosphines, according to its chemical function it is a reagent of the fluorophosphorane group.

Basic Attributes

• CAS No.: 845-64-7
• Chemical formula: C18H15F2P
• English name: difluorotriphenylphosphorane
• Molecular Weight: 300.289
• Exact weight: 300.088
• DSSTox ID: DTXSID00233492
• PSA Features: 0
• XLogP3: 5.7
• Synonyms: F2TPhP, difluorotriphenylphosphane, triphenyldifluorophosphorane, phosphorane difluorotriphenyl-

Substance class and reactivity

Pentacoordinated fluorophosphoranes, which include difluorotriphenylphosphorane, are used in organic synthesis as deoxofluorinating reagents—substances that convert the hydroxyl group of an alcohol into fluoride. The reactivity is determined by the high electrophilicity of the phosphorus(V) atom and the tendency of fluoride ligands to exchange for alkoxy groups with subsequent elimination of the phosphorus-containing fragment (triphenylphosphine oxide).

Scope of application

It is used as a one-reagent system for replacing the hydroxyl group of alcohols with fluorine - a deoxofluorination reaction alternative to the classical reagents DAST and Deoxo-Fluor. It is in demand in laboratory organic synthesis for the production of fluorinated building blocks for pharmaceutical and agrochemical development, as well as in the synthesis of mono- and difluoro-substituted analogues of natural and medicinal compounds.

Sustainability

Like most fluorophosphorane reagents, it is sensitive to moisture: contact with water causes hydrolysis with the formation of triphenylphosphine oxide and hydrogen fluoride. The deoxofluorination reaction is usually carried out in anhydrous aprotic solvents under an inert atmosphere.

Storage and handling

Store in an airtight container, in conditions that exclude moisture, if necessary - in an inert atmosphere, in a cool place. Wear gloves and safety glasses and use a fume hood due to the possible release of corrosive hydrogen fluoride vapors during decomposition. Data on melting point, boiling point, density and official hazard classes are not declared by the supplier.

Batch identification

When ordering, check the batch against the CAS number 845-64-7 and the exact mass of 300.088 - fluorophosphorane reagents are hydrolytically unstable, and batches with expired shelf life may contain a significant proportion of the hydrolysis product, which reduces the efficiency of fluoridation.

Comparison with other deoxofluorinating reagents

Compared to the sulfur-containing reagents of the DAST and Deoxo-Fluor groups, fluorophosphorane systems produce triphenylphosphine oxide as a by-product, a compound that is easily separated by chromatography, which simplifies the purification of the target fluoride on a preparative scale. The choice of a specific deoxofluorinating reagent is determined by substrate specificity: tertiary and benzyl alcohols, which are prone to elimination or rearrangement, require milder conditions and careful selection of the reagent.