Use of pentafluorophenyl esters for one-pot protection/activation of amino and thiol carboxylic acids
作者:Leah M. Gayo、Mark J. Suto
DOI:10.1016/0040-4039(96)00985-9
日期:1996.7
As part of our efforts in the area of combinatorial chemistry, we have been exploring new methods for the construction of combinatorial libraries in a bidirectional fashion. Herein, we describe a new one-pot procedure for the simultaneous protection/activation of amino and thiol carboxylicacids using pentafluorophenyl trifluoroacetate (TFAPfp) and related pentafluorophenyl reagents (FmocPfp and AcPfp)
This study describes firstly the synthesis of benzoxazinones substituted in position 2 by halogenated groups such as -(CH2)n-R(F, Cl) where n = 0, 1 and 2 and R(F, Cl) is a perhalogenated group, and secondly the reaction of these new benzoxazinones with aniline, in different media.Thus it is shown that the behaviour of trifluoromethyl-2-benzoxazinone towards aniline is different, in most cases, in comparison with benzoxazinones substituted by perfluorinated groups CnF2n+1 with n = 2, 3 and 7. Under certain conditions (hot ethanol and aniline with triphenyl phosphite), it is observed that nucleophilic attack of aniline only occurs on the carbonyl group when benzoxazinones are substituted by an electron-withdrawing group such as C2F5, C3F7 and C7F15.