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Name: Hydrogen fluoride-pyridine/PPHF/Pyridine Poly(hydrogen fluoride)/Olah's Reagent
CAS number : 32001-55-1; The 62778-11-4
Molecular formula:C5H5N.nHF(where n≥1)
Appearance: Light yellow to reddish brown transparent liquid
Boiling point: 50℃/1mmHg
Free HF%: 65-70%
Packing: 1kg/ bottle, 25kg/ barrel, 50kg/ barrel
Use: fluorinated reagent
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Hydrogen fluoride-pyridine complex (PPHF) is an improvement on the application form and mode of hydrogen fluoride reagent, which can be simply regarded as hydrogen fluoride with a higher boiling point. The PPHF obtained by Olah reagent preparation method can stabilize the temperature of HF emission to about 55 ℃. Compared with anhydrous hydrogen fluoride, PPHF can probably be considered to have the same reaction, the reaction activity is slightly reduced, the selectivity is greatly increased, and the stereochemistry of the product may be different.
PPHF has been widely used in the fluorination ring opening reaction of oxygen - and nitrogen-containing ternary rings. The ring-opening reaction of epoxide fluoridation that can be accomplished by anhydrous hydrogen fluoride can also be accomplished by PPHF [2], and it has been found that PPHF can obtain better results in some reactions [3]. Usually the reaction can be carried out under very mild conditions with very high stereoselectivity and satisfactory yields (Equation 1)[4,5]. The stereochemistry of the fluorinated ring-opening product of the nitrogen-containing ternary ring is just complementary to the anhydrous hydrogen fluoride reagent (Equation 2)[6]
