Six different fluoroarenes were submitted to the same transformations. Direct deprotonation with alkyllithium or lithium dialkylamide as reagents and subsequent carboxylation afforded acids. These included 2,6-difluorobenzoic acid, 3,6-difluoro-2-iodobenzoic acid, 2-fluoro-6-iodobenzoic acid, 2-fluoro-3-iodobenzoic acid, 2,3-difluoro-4-iodobenzoic acid and 1-fluoro-2-naphthalenecarboxylic acid. If the aryllithium intermediate was trapped with iodine rather than with dry ice, an iodofluoroarene (2, 7, 12, 17, 19, and 24) was formed. Iodoarenes included 1,3-difluoro-2-iodobenzene, 1,4-difluoro-2,3-diiodobenzene, 1-fluoro-2,3-diiodobenzene, 2-fluoro-1,3-diiodobenzene, 2,3-difluoro-1,4-diiodobenzene, and 1-fluoro-2-iodonaphthalene. These, upon treatment with lithium diisopropylamide, underwent deprotonation and iodine migration. The resulting new aryllithium species was intercepted either by carboxylation, to give 2,6-difluoro-3-iodobenzoic acid, 2,5-difluoro-3,6-diiodobenzoic acid, 2-fluoro-3,6-diiodobenzoic acid, 2,3-difluoro-4,6-diiodobenzoic acid, and 1-fluoro-3-iodo-2-naphthalenecarboxylic acid, or by neutralization to produce the iodofluoroarenes which included 2,4-difluoro-1-iodobenzene, 1,4-difluoro-2,5-diiodobenzene, 2-fluoro-1,4-diiodobenzene, 1-fluoro-3-iodonaphthalene. The latter family of compds. was converted into another set of acids, which included 2,4-difluorobenzoic acid, 2,5-difluoro-4-iodobenzoic acid, 1-fluoro-3-naphthalenecarboxylic acid, by subsequent treatment with butyllithium or isopropylmagnesium chloride and carbon dioxide. [on SciFinder (R)]
Title
The basicity gradient-driven migration of iodine: conferring regioflexibility on the substitution of fluoroarenes
Published in
European Journal of Organic Chemistry
Issue
19
Pages
3351-3358
Date
2002
Note
CAN 138:237859 25-17 Benzene, Its Derivatives, and Condensed Benzenoid Compounds Institut de Chimie moleculaire et biologique Ecole Polytechnique Federale, BCh,Lausanne,Switz. Journal 1434-193X written in English. 75-77-4 (Chlorotrimethylsilane); 321-38-0 (1-Fluoronaphthalene); 348-52-7 (1-Fluoro-2-iodobenzene); 372-18-9 (1,3-Difluorobenzene); 462-06-6 (Fluorobenzene); 1121-86-4 (1-Fluoro-3-iodobenzene); 2265-92-1 (1,4-Difluoro-2-iodobenzene); 64248-57-3 (1,2-Difluoro-3-iodobenzene) Role: RCT (Reactant), RACT (Reactant or reagent) (basicity gradient-driven migration of iodine: conferring regioflexibility on substitution of fluoroarenes); 385-00-2P (2,6-Difluorobenzoic acid); 2265-93-2P (2,4-Difluoro-1-iodobenzene); 13671-00-6P (2,6-Difluorobenzoic acid methyl ester); 13697-89-7P (1,3-Difluoro-2-iodobenzene); 147808-02-4P (2-Fluoro-1,4-diiodobenzene); 189095-25-8P (1,4-Difluoro-2,5-diiodobenzene); 447464-03-1P (2-Fluoro-3-iodobenzoic acid); 501432-99-1P (1,4-Difluoro-2,3-diiodobenzene); 501433-02-9P (1-Fluoro-2,3-diiodobenzene); 501433-05-2P (2,3-Difluoro-4-iodobenzoic acid); 501433-06-3P (2,3-Difluoro-1,4-diiodobenzene); 501433-08-5P; 501433-09-6P (1-Fluoro-2-iodonaphthalene); 501433-11-0P (1-Fluoro-3-iodonaphthalene); 501433-13-2P (3,6-Difluoro-2-iodobenzoic acid methyl ester); 501433-14-3P (2,6-Difluoro-3-iodobenzoic acid methyl ester); 501433-15-4P (2-Fluoro-3,4-diiodobenzoic acid methyl ester); 501433-16-5P ((2-Fluoro-3-iodophenyl)trimethylsilane) Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (basicity gradient-driven migration of iodine: conferring regioflexibility on substitution of fluoroarenes); 574-97-0P (1-Fluoro-2-naphthalenecarboxylic acid); 1583-58-0P (2,4-Difluorobenzoic acid); 13772-61-7P (1-Fluoro-3-naphthalenecarboxylic acid); 111771-08-5P (2-Fluoro-6-iodobenzoic acid); 124700-40-9P (2-Fluoro-4-iodobenzoic acid); 229178-74-9P (2,6-Difluoro-3-iodobenzoic acid); 333780-74-8P (2,3-Difluoro-5-iodobenzoic acid); 501432-98-0P (3,6-Difluoro-2-iodobenzoic acid); 501433-00-7P (2,5-Difluoro-3,6-diiodobenzoic acid); 501433-01-8P (2,5-Difluoro-4-iodobenzoic acid); 501433-03-0P (2-Fluoro-3,6-diiodobenzoic acid); 501433-04-1P (2-Fluoro-1,3-diiodobenzene); 501433-07-4P (2,3-Difluoro-4,6-diiodobenzoic acid); 501433-10-9P (1-Fluoro-3-iodo-2-naphthalenecarboxylic acid); 501433-12-1P; 501433-17-6P Role: SPN (Synthetic preparation), PREP (Preparation) (basicity gradient-driven migration of iodine: conferring regioflexibility on substitution of fluoroarenes)
Record creation date
2006-03-03