Concise stereoselective synthesis of 1-perfluoroalkyl enamines via the addition of N-lithiated amines to enol ethers and their subsequent metalation to form new functionalized enamines
作者:Jean-Pierre Bégué、Danièle Bonnet-Delpon、Denis Bouvet、Michael H. Rock
DOI:10.1039/a801243a
日期:——
Addition of lithium amides derived from a range of cyclic, sterically demanding, and chiral amines, to trifluoromethyl (Z)-enol ethers 1 and 4, provides stereoselectively the corresponding (Z)-enamines 3a–e and 7 in good yields. This reaction has been extended to the perfluoroalkyl and chlorofluoroalkyl enol ethers (CF2Cl, C2F5). The enamines can react with ButLi to give vinylic anions and, after quenching with aldehydes and ethyl chloroformate, provide new functionalized enamines 12–16.
Z-trifluoromethyl thioenol ethers, enol ethers, and enamines; reactivity towards organolithium reagents
作者:Jean-Pierre Bégué、Danièle Bonnet-Delpon、Michael H. Rock
DOI:10.1016/0040-4039(95)02118-3
日期:1996.1
conjugated with an unsaturation in the β-position undergo addition/elimination reactions with organolithium reagents to yield the corresponding trifluoromethyl alkenes while preserving the geometry of the double bond. Trifluoromethyl enamines exhibit a different reactivitytowards organolithium reagents with a vinyl anion being formed in preference to addition/elimination products.
This work describes the optimization process for the synthesis of β-trifluoromethylated ketonesfrom trifluoromethylated allylicalcohols. This transformation proceeds through a ruthenium catalyzed isomerization under mild conditions with high atom economy. The effect of the CF3 group was analyzed and it provides fundamental insights into the isomerization reaction.
Regioselective ring opening of various substituted perfluoroepoxy ethers was achieved with magnesium bromide, leading to new α-bromofluoroalkyl ketones in good yields.
The Wittig reaction of perfluoro acid derivatives: access to fluorinated enol ethers, enamines, and ketones
作者:Jean Pierre Begue、Daniele Bonnet-Delpon、Dany Mesureur、Gerard Nee、Sheng Wen Wu
DOI:10.1021/jo00040a017
日期:1992.7
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.