Reagents and process for direct C—H functionalization
The present invention refers to a process for direct C—H functionalization, the reagents used in the process and the use thereof for the direct C—H functionalization as well as the so-obtained products.
1. A process for preparing an aromatic or heteroaromatic thianthrenium salt, comprising reacting a monocyclic or polycyclic, aromatic or heteroaromatic hydrocarbon Ar, which may be substituted or unsubstituted, with an activated thianthrene derivative of the Formula (I) or mixtures thereof in an organic solvent whereby a thianthrenium salt of the Formula (III) is obtained:
wherein R 1 to R 8 may be the same or different and are selected from hydrogen, Cl, F, a partially or fully fluorinated C 1 to C 6 alkyl group, n is 0 or 1, RX is selected from HBF 4 ; HBF 4 ·OEt 2 , BF 3 ·OEt 2 , trifluoro methane sulfonic acid (triflic acid), triflic acid anhydride, trifluoro acetic acid, trifluoro acetic acid anhydride, trimethylsilyltriflate and X is an anion derived from RX.
2. Process for preparing a thianthrenium salt compound of the Formula (III) according to claim 1 , wherein the thianthrene derivative of the Formula (I) is activated by adding a carboxylic acid anhydride if n=1 in formula (I).
3. Process for preparing a thianthrenium salt of the Formula (III) according to claim 2 , wherein the reaction is carried out in the presence of a Brönstedt acid or Lewis acid.
4. Process for preparing a thianthrenium salt of the Formula (III) according to claim 1 , wherein the thianthrene derivative of the Formula (I) is activated by oxidation if n=0 in formula (I).
5. Process for preparing a thianthrenium salt of the Formula (III) according to claim 4 , wherein the thianthrene derivative of the Formula (I) is activated by oxidation with 1-Chloromethyl-4-fluoro-1,4-diazonia bicyclo[2.2.2]octane bis(tetrafluoroborate).
6. Process for preparing a thianthrenium salt of the Formula (III) according to claim 4 , wherein the thianthrene derivative of the Formula (I) is activated by electrochemical oxidation.
7. Process for preparing a thianthrenium salt of the Formula (III) according to claim 5 , which comprises reacting an electron-poor Ar and a thianthrene derivative of the Formula (I) or a mixture of different thianthrene derivatives of the Formula (I), wherein R 2 , R 3 , R 6 and R 7 are F or CF 3 and the others of R 1 to R 8 are hydrogen and wherein n is 0 or 1.
8. Process for preparing an aromatic or heteroaromatic thianthrenium salt according to claim 1 , which comprises reacting an electron-rich Ar and a thianthrene derivative of the Formula (I) or a mixture of different thianthrene derivatives of the Formula (I), wherein R 1 to R 8 are hydrogen and wherein n is 0 or 1.
9. Thianthrenium salt of the Formula (III):
wherein R 1 to R 8 may be the same or different and are selected from hydrogen, Cl, F, a partially or fully fluorinated C 1 to C 6 alkyl group, but wherein at least one of R 1 to R 8 is not hydrogen, and Ar is a monocyclic or polycyclic, aromatic or heteroaromatic hydrocarbon Ar, which may be substituted or unsubstituted, and X − is an anion.
10. Thianthrenium salt of the Formula (III) as defined in claim 9 , wherein R 2 , R 3 , R 6 and R 7 are F or CF 3 and the others of R 1 to R 8 are hydrogen and wherein Ar and X − have the meaning as given in claim 9 .
11. Method comprising conducting a process selected from the group consisting of a photoredox catalysis reaction, a photoredox functionalization, and a radical arylation, and as a part of said process reacting a thianthrenium salt of the Formula (III) according to claim 9 with another reactant of the process.
12. Method comprising conducting a transition metal catalyzed cross coupling reaction, and as a part of said transition metal catalyzed cross coupling reaction reacting a thianthrenium salt of the Formula (III) according to claim 9 with another reactant of the transition metal catalyzed cross coupling reaction.
13. Method as defined in claim 12 , wherein the transition metal catalyzed cross coupling reaction is selected from a Heck reaction, a Sonogashira reaction, a Negishi reaction, a Suzuki reaction, and a carbonylation reaction.