Dianion Approach to Chiral Cyclopropene Carboxylic Acids
作者:Lian-an Liao、Ni Yan、Joseph M. Fox
DOI:10.1021/ol047837+
日期:2004.12.1
[reaction: see text] In this Letter, we describe a general method for preparing the dianions of cyclopropene carboxylic acids, and we show that their subsequent reactions with electrophiles provide a general means for selectively introducing diverse types of functional groups. This provides a general method for the synthesis of chiral 1,2-disubstituted cyclopropenes, and opens new avenues for the enantioselective
A Reactivity/Affinity Switch for Parallel Kinetic Resolution: α-Amino Acid Quasienantiomers and the Resolution of Cyclopropene Carboxylic Acids
作者:Lian-an Liao、Fan Zhang、Olga Dmitrenko、Robert D. Bach、Joseph M. Fox
DOI:10.1021/ja049779t
日期:2004.4.1
type of parallel kineticresolution (PKR) is reported in which quasienantiomers with very similar reactivities give products whose chromatographic properties diverge upon the addition of fluoride. This concept of a reactivity/affinity switch is applied to the PKR of cyclopropene carboxylicacids with all-carbon quaternary centers. This is the first application of alpha-amino acid quasienantiomers in