Preparing imidazolium salts, preferably 1,3-disubstiuted imidazolium salts, useful e.g. as precursors of N-heterocyclic carbenes, comprises reducing 1,3-disubstituted-2-alkoxyimidazolium salts with hydrides and/or hydride donors

摘要

Preparing imidazolium salts (II) comprises reducing 1,3-disubstituted-2-alkoxyimidazolium salts (I) with hydrides and/or hydride donors. Preparing imidazolium salts of formula (II) comprises reducing 1,3-disubstituted-2-alkoxyimidazolium salts of formula (I) with hydrides and/or hydride donors. Either R1-R5 : H, 1-20C-alkyl, 2-20C-alkenyl with one or more double bonds, 2-20C-alkynyl with one or more triple bonds or optionally partially or completely saturated 3-10C-cycloalkyl (optionally substituted with 1-10C-alkyl); or R1R2, R1R3 or R3R4 bounded by single-, double- or triple-bonds : 3-8-membered ring to form bi-, tri- or poly-cyclic cations, where R1-R5 in any position are partially or completely substituted by halogen (preferably F, Cl, Br or I) or in any position is partially substituted by CN or NO 2, a carbon atom of one or more substituents of R1-R5 is optionally substituted by atom and/or atom groups comprising -O-, -C(O)-, -C(O)O-, -S-, -S(O)-, -SO 2-, -SO 3-, -N=, -N=N-, -NH-, -NR1a-, -PR1a-, -P(O)R1a, -P(O)R1a-O-, -O-P(O)R1a-O- or -P(R1a) 2=N-, and R1a is not fluorinated, partially or perfluorinated 1-6C-alkyl, saturated or partially unsaturated 3-7C-cycloalkyl, optionally substituted phenyl or optionally substituted heterocycle; A -F -, Cl -, Br -, I -, CN -, [ClO 4] -, [BF 4] -, [BF zR(f) 4 - z] -, [BF z(CN) 4 - z] -, [B(CN) 4] -, [B(C 6F 5) 4] -, [B(OR6) 4] -, [N(CF 3) 2] -, [N(CN) 2] -, [AlCl 4] -, [SbF 6] -, [SiF 6] -, [R6SO 3] -, [R(f)SO 3] -, [(R(f)SO 2) 2N] -, [(R(f)SO 2) 3C] -, [(FSO 2) 3C] -, [R6CH 2OSO 3] -, [R6C(O)O] -, [R(f)C(O)O] -, [CCl 3C(O)O] -, [(CN) 3C] -, [(CN) 2CR6] -, [(R6O(O)C) 2CR6] -, [P(C nF 2 n + 1 - mH m) yF 6 - y] -, [P(C 6F) yF 6 - y] -, [R6 2P(O)O] -, [R6P(O)O 2] 2 -, [(R6O) 2P(O)O] -, [(R6O)P(O)O 2] 2 -, [(R6O)(R6)P(O)O] -, [R(f) 2P(O)O] -or [R(f)P(O)O 2] 2 -, where A -contains at least two substituents R(f), and at least two R6, in which R(f) are bounded together by single or double bonds to form 3-8 membered ring, and R6 are bounded together by single or double bonds to form 3-8 membered ring; R(f) : perfluorinated and optionally branched 1-20C-alkyl, perfluorinated and optionally branched 2-20C-alkenyl with one or more double bonds, perfluorinated phenyl and optionally partially or completely saturated 3-7C-cycloalkyl, which is optionally substituted by perfluoroalkyl, where a carbon atom or two non-adjacent carbon atoms of R(f) are optionally substituted by atoms and/or atom groups comprising -O-,-C(O)-, -S-,-S(O)-,-SO 2-, -N=, -N=N-,-NR1a-, -PR1a-, -P(O)R1a, R1a-O-SO 2- or R1a-OC(O)-; R6 : H, linear or branched 1-20C-alkyl, 2-20C-alkenyl with one or more double bonds, 2-20C-alkynyl with one or more triple bonds or optionally partially or completely saturated 3-10C-cycloalkyl, which is optionally substituted with 1-10C-alkyl, where R6 is partially substituted by CN -or NO 2-, F -, Cl -, Br -or I -, and a carbon atom of R6 are optionally substituted by atoms and/or atom groups comprising -O-, -C(O)-, -C(O)O-, -S-, -S(O)-, -SO 2-, -SO 3-, -N=, -N=N-, -NH-, -NR1a-, -PR1a- and -P(O)R1a, -P(O)R1a-O- or -O-P(O)R1a-O-, -P(R1a) 2=N-, -C(O)NH-, -C(O)NR1a, -SO 2NH- or -SO 2NR1a-; n : 1-20; m, z : 0-3; and y : 0-4. [Image].