A new method for making acyl fluorides using BrF3

Chemical Modification of Oligonucleotides for Therapeutic, Bioanalytical and other Applications

“…Acyl fluorides could also be formed by either direct reaction of the reagent with carboxylic acids or with acyl chlorides, the second process more general and yielding usually better results. Bromine trifluoride is also able to react with tert ‐butyl esters and turn them into acyl fluorides although in somewhat lower yields 35. The last reaction resembles very much the reaction of BrF 3 with polymeric tert ‐butyl sulfones which when reacted with BrF 3 produced the corresponding sulfonyl fluorides (Scheme ) 36…”

Selective Reactions of Bromine Trifluoride in Organic Chemistry

“…Bromine trifluoride is also able to react with tert-butyl esters and turn them into acyl fluorides although in somewhat lower yields. [35] The last reaction resembles very much the reaction of BrF 3 with polymeric tert-butyl sulfones which when reacted with BrF 3 produced the corresponding sulfonyl fluorides (Scheme 11). [36] …”

“…[21] The above type of reactions was also used for the synthesis of 2-fluoroacrylic acid or acyl halide (32). The 1-chloro-2,3-dibromopropane (33) was reacted with bromine trifluoride to form a mixture of 1-chloro-2-fluoro-3-bromopropane (34) and 1-chloro-2,3,-difluoropropane (35), which were then acetolized with AcOK, oxidized and dehydrohalogenated to yield 32. [22] This important compound was also made by reacting a-halo acids or esters with BrF 3 .…”

Acyl Fluorides in Late‐Transition‐Metal Catalysis

“…Aclassical and reliable procedure for the synthesis of acyl fluorides is the treatment of carboxylic acids or derivatives thereof (e.g., carboxylic acid anhydrides or acyl chlorides) with fluorinating reagents [5,18] to induce deoxyfluorination or halogen exchange reactions (Scheme 4A). Thus far, various inorganic and organic fluorination reagents have been employed for this purpose:H F, [19] NaF, [20] KF, [21] KHF 2 , [22] CsF, [23] ZnF 2 , [24] HBF 4 , [25] Na 2 SiF 6 , [26] Bu 4 NF (TBAF), [27] SbF 3 , [28] KSO 2 F, [29] SeF 4 , [30] F 2 (aerosol), [31] BrF 3 , [32] XeF 2 , [33] SF 4 , [34] R 2 NÀSF 3 (DAST, [35] morpholinosulfur trifluoride, [36] and Deoxo-Fluor [37] ), (R 2 N=SF 2 )BF 4 (XtalFluor), [38] ArSF 3 (Fluolead), [39] (Me 4 N)SCF 3 , [40] cyanuric fluoride, [6,41] 2-fluoropyridinium salts, [42] fluoro formamidinium salts (TFFH and BTFFH), [43] perfluoroalkylamines (e.g.,Y arovenkosreagent and Ishikawasr eagent), [44] PhCOF, [45] and other Fs ources (Scheme 4B). [46] Among these synthetic methods,the following fluorinating reagents are especially practical and useful: HF, [19] DAST, [35] Deoxo-Fluor [37] (Me 4 N)SCF 3 , [40] and cyanuric fluoride.…”