Trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper
A literature method reported for the prepn. of trifluoromethyl substituted benzenes from iodobenzene and congeners was successfully extended to the pyridine series. 2-Iodopyridines can be converted into 2-(trifluoromethyl)pyridines almost quant. by displacement of iodide by (trifluormethyl)copper generated in situ from (trifluoromethyl)trimethylsilane in the presence of cuprous iodide and potassium fluoride. In contrast, yields are moderate at best if 3- and 4-iodopyridines or 2-bromopyridines are used as the starting materials. [on SciFinder (R)]
2002
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CAN 137:33189 27-16 Heterocyclic Compounds (One Hetero Atom) Section de Chimie (BCh),Universite Lausanne,Lausanne,Switz. Journal 1434-193X written in English. 624-28-2 (2,5-Dibromopyridine); 625-92-3 (3,5-Dibromopyridine); 626-05-1 (Pyridine, 2,6-dibromo); 1120-90-7 (3-Iodopyridine); 5029-67-4 (2-Iodopyridine); 15854-87-2 (4-Iodopyridine); 73290-22-9 (Pyridine, 2-bromo-5-iodo); 75806-85-8 (2,3,5-Tribromopyridine); 78607-36-0 (Pyridine, 2-chloro-3-iodo); 153034-86-7 (Pyridine, 2-chloro-4-iodo); 223463-13-6 (Pyridine, 5-bromo-2-iodo); 233770-01-9 (Pyridine, 3-bromo-5-iodo); 234111-08-1 (Pyridine, 2-bromo, 6-iodo) Role: RCT (Reactant), RACT (Reactant or reagent) (prepn. of trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper); 5140-72-7P (Pyridine, 2-bromo, 6-chloro); 258506-66-0P (Pyridine, 2-chloro, 6-iodo); 436799-34-7P; 436799-35-8P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. of trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper); 7681-65-4 (Copper iodide (CuI); 7789-23-3 (Potassium fluoride (KF); 81290-20-2 ((Trifluoromethyl)trimethylsilane) Role: RGT (Reagent), RACT (Reactant or reagent) (prepn. of trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper); 368-48-9P (2-Pyridinetrifluoromethyl); 3796-23-4P (3-Pyridinetrifluoromethyl); 3796-24-5P (4-Pyridinetrifluoromethyl); 39890-95-4P (Pyridine, 2-chloro-6-trifluoromethyl); 50488-42-1P (Pyridine, 2-bromo-5-(trifluoromethyl); 65753-47-1P (Pyridine, 2-chloro-3-(trifluoromethyl); 81565-18-6P (Pyridine, 2-chloro-4-(trifluoromethyl); 189278-27-1P (Pyridine, 2-bromo-6-trifluoromethyl); 436799-32-5P; 436799-33-6P; 436799-36-9P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper)
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