Three chloro(trifluoromethyl)pyridines as model substrates for regioexhaustive functionalization
As a further test of the concept of regioexhaustive functionalization, 2-chloro-6-(trifluoromethyl)pyridine, 2-chloro-5-(trifluoromethyl)pyridine and 3-chloro-4-(trifluoromethyl)pyridine were each converted into the three possible carboxylic acids. This was achieved by employing several, but not all of the organometallic "toolbox methods"; transformation of a more basic organometallic species into a less basic isomer by transmetalation-equilibration, site discriminating deprotonation with lithium N,N-diisopropylamide or lithium 2,2,6,6-tetramethylpiperidide, regio-divergent iodine migration and steric screening of acidic positions by a bulky trialkylsilyl group. [on SciFinder (R)]
WOS:000224142400004
2004
18
3793
3798
CAN 141:424098 27-16 Heterocyclic Compounds (One Hetero Atom) Institut de Chimie moleculaire et biologique,Ecole Polytechnique Federale,Lausanne,Switz. Journal 1434-193X written in English. 39890-95-4 (2-Chloro-6-(trifluoromethyl)pyridine); 52334-81-3 (2-Chloro-5-(trifluoromethyl)pyridine); 77332-79-7 (3-Chloro-4-iodopyridine); 81290-20-2 (Trimethyl(trifluoromethyl)silane); 205240-59-1 Role: RCT (Reactant), RACT (Reactant or reagent) (regioexhaustive functionalization of chloro(trifluoromethyl)pyridines); 81565-19-7P (3-Chloro-4-(trifluoromethyl)pyridine); 205444-18-4P; 205444-22-0P; 505084-55-9P; 505084-56-0P; 518057-64-2P; 796090-26-1P; 796090-29-4P; 796090-30-7P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (regioexhaustive functionalization of chloro(trifluoromethyl)pyridines); 261635-83-0P; 280566-45-2P; 505084-58-2P; 505084-59-3P; 518989-97-4P; 796090-23-8P; 796090-24-9P; 796090-25-0P; 796090-27-2P; 796090-28-3P; 796090-31-8P Role: SPN (Synthetic preparation), PREP (Preparation) (regioexhaustive functionalization of chloro(trifluoromethyl)pyridines)
REVIEWED
EPFL