The Wittig reaction of perfluoro acid derivatives: access to fluorinated enol ethers, enamines, and ketones
摘要:
The preparation of novel perfluoroalkyl-substituted compounds in good yields is described. This preparation involves the Wittig reaction of a phosphonium ylide with perfluoroalkyl acid derivatives. The influence of the structure of the starting alkylidenetriphenylphosphoranes, the perfluoroalkyl reagents, and the reaction conditions has been investigated. Trifluoroacetamides lead to a Z/E mixture of enamines 3. Perfluoroalkyl esters (Rf = CF3, C2F5, C3F7, C7F15, CF2Cl) lead to only the (Z)-enol ethers 8-12 when reactions are performed with NaNH2 as a base and to 1-perfluoroalkyl ketones 13-17 when reactions are performed with BuLi.
Halogenation of 1-trifluoromethyl enamines: A new and efficient synthesis of α-bromo- and α-iodo-trifluoromethyl ketones
作者:Jean-Pierre Bégué、Daniéle Bonnet-Delpon、Denis Bouvet、Michael H. Rock
DOI:10.1016/s0022-1139(96)03453-7
日期:1996.9
Treatment of the 1-trifluoromethyl enamines 1a-d with bromine or iodine results in the formation of the corresponding iminium salts. Treatment of any of these salts with methanol results in the formation of the corresponding alpha-halo-trifluoromethyl ketones.