Superbase reactions: the expedient and selective metalation of fluorine- or trifluoromethyl-substituted benzenes

When treated with the superbasic mixt. of butyllithium and potassium tert-butoxide, fluorobenzene, difluorobenzenes, fluoro(trifluoromethyl)benzenes, (trifluoromethyl)benzene and bis(trifluoromethyl)benzenes undergo site-selective hydrogen-metal exchange. Best results are obtained in THF solns. at -75 Deg or -50 Deg. Upon quenching with carbon dioxide the corresponding carboxylic acids are obtained in good to excellent yield. [on SciFinder (R)]


Published in:
Synlett, 12, 747-8
Year:
1990
Keywords:
Note:
CAN 114:206685
25-17
Benzene, Its Derivatives, and Condensed Benzenoid Compounds
Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz.
Journal
0936-5214
written in English.
594-19-4 Role: RCT (Reactant), RACT (Reactant or reagent) (metalation with, of bis(trifluoromethyl)benzene with subsequent carbon dioxide quenching); 344-96-7P (Methyl 2-(trifluoromethyl)benzoate); 433-97-6P (2-(Trifluoromethyl)benzoic acid); 444-30-4P; 445-29-4P (2-Fluorobenzoic acid); 725-89-3P (3,5-Bis(trifluoromethyl) benzoic acid); 2991-28-8P (2,5-Difluorobenzoic acid); 4519-39-5P (2,3-Difluorobenzoic acid); 24821-22-5P (2,6-Bis(trifluoromethyl)benzoic acid); 32890-87-2P (2,4-Bis(trifluoromethyl)benzoic acid); 32890-94-1P (2-Fluoro-6-(trifluoromethyl)benzoic acid); 115029-22-6P (2-Fluoro-3-(trifluoromethyl)benzoic acid); 115029-23-7P (2-Fluoro-5-(trifluoromethyl)benzoic acid) Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 3030-47-5 Role: RCT (Reactant), RACT (Reactant or reagent) (regioselective metalation of bis(trifluoromethyl)benzene with secondary butyllithium in presence of); 598-30-1 Role: RCT (Reactant), RACT (Reactant or reagent) (regioselective metalation of bis(trifluoromethyl)benzene with, in presence of pentamethyldiethylenetriamine); 98-08-8 ((Trifluoromethyl)benzene); 367-11-3 (1,2-Difluorobenzene); 392-85-8 (1-Fluoro-2-(trifluoromethyl)benzene); 401-80-9 (1-Fluoro-3-(trifluoromethyl)benzene); 402-31-3 (1,3-Bis(trifluoromethyl)benzene); 402-44-8 (1-Fluoro-4-(trifluoromethyl)benzene); 462-06-6 (Fluorobenzene); 540-36-3 (1,4-Difluorobenzene) Role: RCT (Reactant), RACT (Reactant or reagent) (regioselective metalation of, with butyllithium/potassium tertiary butoxide superbase system, with subsequent carbon dioxide quenching); 865-47-4 Role: RCT (Reactant), RACT (Reactant or reagent) (superbase contg. butyllithium and, for regioselective metalation of fluoro- or trifluoromethyl-substituted benzenes); 109-72-8 (Butyllithium) Role: RCT (Reactant), RACT (Reactant or reagent) (superbase contg. potassium tertiary butoxide and, from regioselective metalation of fluoro- or trifluoromethyl-substituted benzenes)
Laboratories:




 Record created 2006-03-03, last modified 2018-01-27


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