Selective Formal Transesterification of Fluorinated 2-(Trimethylsilyl)ethyl α-Imino Esters Mediated by TBAF
作者:Santos Fustero、María Sánchez-Roselló、Vanessa Rodrigo、Amador García、Silvia Catalán、Carlos del Pozo
DOI:10.1021/jo800567a
日期:2008.7.1
The scope of the transesterification reaction between β-fluorinated α-imino esters and various electrophiles in the presence of TBAF as fluorine source is described. The reaction is highly selective for alkyl iodides, bromides, and mesylates, while alkyl chlorides react at a significantly slower rate and tosylates do not react under the reaction conditions. This methodology represents a simple and
Solution-, Solid-Phase, and Fluorous Synthesis of β,β-Difluorinated Cyclic Quaternary α-Amino Acid Derivatives: A Comparative Study
作者:Santos Fustero、María Sánchez-Roselló、Vanessa Rodrigo、Juan F. Sanz-Cervera、Julio Piera、Antonio Simón-Fuentes、Carlos del Pozo
DOI:10.1002/chem.200702009
日期:2008.8.8
The diastereoselective synthesis of cyclic beta,beta-difluorinated alpha-amino acid derivatives bearing a quaternary stereocenter is described. The process relies on the chemo- and diastereoselective addition of allylic organometallic reagents to fluorinated alpha-imino esters and a subsequent ring-closingmetathesis reaction (RCM). Complete selectivity in the nucleophilic addition was achieved with