Electrochemical fluorination. Part I. Electrochemical fluorination of alkyl-substituted pyridines

Abstract

Electrochemical fluorination of various alkyl-substituted pyridines affords the corresponding perfluoro-(N-fluoroalkylpiperidines) in yields [pyridine (8%), 2-methylpyridine (13%), 3-methylpyridine (2%), 2-ethylpyridine (1%), 2,4-dimethylpyridine (11%), 2,6-dimethylpyridine (26%), 3,5-dimethylpyridine (2%), and 2,4,6-trimethylpyridine (10%)] which depend to a large extent on the position and number of alkyl substituents. Electrochemical fluorination provides a useful route to fluorocarbons of structures corresponding to the original carbon skeletons in the alkylpyridine, together with related fluorocarbons produced by chain degradation. The production of other fluorocarbons reveals that carbon skeleton rearrangement can occur, but to only a minor extent, during electrochemical fluorination.