Diastereoselective Synthesis of Fluorinated, Seven-Membered β-Amino Acid Derivatives via Ring-Closing Metathesis
摘要:
[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.
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
Cross-Metathesis Reactions as an Efficient Tool in the Synthesis of Fluorinated Cyclic β-Amino Acids
作者:Santos Fustero、María Sánchez-Roselló、José Luis Aceña、Begoña Fernández、Amparo Asensio、Juan F. Sanz-Cervera、Carlos del Pozo
DOI:10.1021/jo900296d
日期:2009.5.1
The synthesis of enantiomerically pure, cyclic, γ,γ-difluorinated β-amino acids with various ring sizes has been carried out with a cross-metathesis (CM) reaction being one of the key steps, followed by a Dieckmann-type condensation to bring about the cyclization. Subsequent catalytic hydrogenation under microwave irradiation with (−)-8-phenylmenthol as a chiral auxiliary led to the successful chemo-