691889-40-4Relevant academic research and scientific papers
A Reactivity/Affinity Switch for Parallel Kinetic Resolution: α-Amino Acid Quasienantiomers and the Resolution of Cyclopropene Carboxylic Acids
Liao, Lian-An,Zhang, Fan,Dmitrenko, Olga,Bach, Robert D.,Fox, Joseph M.
, p. 4490 - 4491 (2004)
A new type of parallel kinetic resolution (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 carboxylic acids with all-carbon quaternary centers. This is the first application of α-amino acid quasienantiomers in PKR, and it is a complementary approach for acyltransfer systems where the asymmetry is induced by the nucleophile rather than the leaving group. Excellent diastereoselectivities (ranging from 90:10 to 99.5:5) and good yields were obtained for both quasienantiomeric products, and the reactions can be run on significant scale because the separation is trivial. High-level DFT calculations (B3LYP functional with the 6-31+G(d,p) basis set) provided transition-state structures with relative energies that are in accord with the experimental observations. Copyright
