A regio- and stereoisomeric study of allylic alcohol fluorination with a range of reagents

Efficient regio- and stereoselective access to novel fluorinated β-aminocyclohexanecarboxylates

“…There is currently extensive research activity in synthetic chemistry for the preparation of various biologically active fluorinated products [1–10]. …”

Fluoroalkyl Amino Reagents (FARs): A General Approach towards the Synthesis of Heterocyclic Compounds Bearing Emergent Fluorinated Substituents

“…Since the 1960s till today, the Petrov reagent ( 1a ), the Yarovenko reagent ( 1b ) and the Ishikawa reagent ( 1c ) have been commonly used as selective fluorination agents of compounds containing a hydroxyl moiety, such as alcohols [ 18 , 19 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ], including hydroxyproline [ 50 , 51 , 52 , 53 ] or carbohydrate derivatives [ 54 ], sulfonic [ 19 ] and carboxylic acids [ 55 , 56 , 57 , 58 ]. Interestingly, carbonyl compounds can also react with FARs to afford difluoromethylated compounds [ 59 ].…”

4-tert-Butyl-2,6-dimethylphenylsulfur trifluoride

“…The other (method B) is to heat a mixture of 1, a carboxylic acid, and Py·9HF at 50 • C in an open reactor (atmospheric pressure). The fluorination of 4-methoxycinnamic acid with 1 (3.5 equiv) is performed in 75% yield in the presence of 0.3 equiv of Et 3 N(HF) 3 , while it gives a complex mixture without Et 3 N(HF) 3 . 1 The conversion of carboxylic acids to CF 3 compounds with solid 1 is very useful, as it provides an alternative to the gaseous and toxic SF 4 .…”

“…1 A primary alcohol is fluorinated in high yield when it is reacted with 1 at 85 • C, followed by treatment with 70 wt% HF-pyridine (Py·9HF; Olah's reagent) at 50 • C (eq 1). 1 Secondary alcohols, 1 benzyl alcohols, 1 and allyl alcohols 1,2 are fluorinated with 1 at 0 • C to room temperature in the presence of Et 3 N(HF) 3 as an additive in better yields than without the additive (eq 2). Fluorination of allyl alcohols is accompanied with rearranged fluoro products.…”

“…1 The fluorination of hydroxyls group proceeds with inversion of configuration (eq 4). 1 n-C 10 H 21 CH(OH)CH 3 1 Et 3 N(HF) 3 in CH 2 Cl 2 0 ºC, 0.5 h to rt, 3 h n-C 10 H 21 CHFCH 3…”