Continuous deoxyfluorination with sf4

A method for deoxyfluorination of anyone of substrates a), b), c) and d), by a reaction of said substrate a), b), c) or d) with the fluorination reagent SF4 in the presence of at least 1 equiv of a base, the equiv are molar equiv based on the molar amount of substrate;

• the reaction is done in a continuous flow reaction mode;
• wherein
• substrate a) is a primary or secondary alcohol, or
• substrate a) is a di-, tri- or tetra-peptide of natural alpha amino acids containing a primary or secondary aliphatic OH residue in its side chain,
• substrate b) is an aldehyde,
• substrate c) is a carboxylic acid, and
• substrate d) is an unsubstituted or substituted cyclohexanone of formula (D6) or an unsubstituted or substituted cyclohexenone of formula (D6), or an unsubstituted or substituted cyclopentanone of formula (D5) or an unsubstituted or substituted cyclopentenone of formula (D5),
• and wherein
• in case of substrate a) the hydroxyl residue of the primary or secondary alcohol is exchanged against fluorine providing the respective (mono)fluorine compound;
• in case of substrate b) the oxo residue of the aldehyde group of the aldehyde is exchanged against two geminal fluorine atoms providing the respective difluoro compound;
• in case of substrate c) the hydroxyl residue of the carboxylic acid is exchanged against fluorine providing the respective acid fluoride;
• in case of substrate d) the oxo residue of the keto group is exchanged against fluorine providing a vinyl fluoride compound of formula (D6-F) or of formula (D5-F) respectively according to Scheme D,
• wherein in formula (D6) and formula (D6-F) the three endocyclic bonds C3-C4, C4-C5 and C5-C6 are either single bonds or one of said three bonds is a double bond and the other two bonds of said three bonds are single bonds, and
• wherein in formula (D5) and formula (D5-F) the two endocyclic bonds C3-C4 and C4-C5 are either single bonds or one of said two bonds is a single bond and the other bond of said two bonds is a double bond.