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
Asymmetric Synthesis of Fluorinated Cyclic β-Amino Acid Derivatives through Cross Metathesis
作者:Santos Fustero、María Sánchez-Roselló、Juan F. Sanz-Cervera、José Luis Aceña、Carlos del Pozo、Begoña Fernández、Ana Bartolomé、Amparo Asensio
DOI:10.1021/ol061892w
日期:2006.9.1
The asymmetric synthesis of several fluorinated cis-2-aminocycloalkane carboxylic acids (cis-2-ACACs) with a cross metathesis (CM) reaction as the key step has been carried out, constituting the first time a metathesis protocol has been undertaken with fluorinated imidoyl chlorides. Subsequent chemoselective hydrogenation of the olefin moiety, Dieckmann condensation, and stereoselective reduction of
Enantioselective Synthesis of Fluorinated α-Amino Acids and Derivatives in Combination with Ring-Closing Metathesis: Intramolecular π-Stacking Interactions as a Source of Stereocontrol
[GRAPHICS]Hydride reduction of C=N bonds stereocontrolled by intramolecular m-stacking interactions of 1-naphthylsulfinyl and N-aryl groups, nonoxidative Pummerer rearrangement, and ring-closing metathesis are efficiently combined in a highly stereoselective entry to enantiomerically pure cyclic and acyclic fluorinated beta -amino alcohols and alpha -amino acid derivatives, respectively.
Diastereoselective Synthesis of Fluorinated, Seven-Membered β-Amino Acid Derivatives via Ring-Closing Metathesis
作者:Santos Fustero、Ana Bartolomé,、Juan F. Sanz-Cervera、María Sánchez-Roselló、Juan García Soler、Carmen Ramírez de Arellano、Antonio Simón Fuentes
DOI:10.1021/ol034827k
日期:2003.7.1
[GRAPHICS]Cis and trans seven-membered gamma,gamma-difluorinated beta-amino acid derivatives (III) have been prepared with a sequence that starts with imidoyl halides (I), which are condensed with suitable ester enolates to give intermediates (II). These, in turn, can be cyclized by means of a ringclosing olefin metathesis reaction and the product stereoselectively reduced to yield compounds (III) in good overall yields.