Amplification Of Enantiomeric Excess Research Articles

Asymmetric autocatalysis of 5-carbamoyl-3-pyridyl alkanols with amplification of enantiomeric excess

5-Carbamoyl-3-pyridyl alkanols with low e.e. act as asymmetric autocatalysts in the consecutive asymmetric autocatalytic addition of diisopropylzinc to 5-carbamoyl-3-pyridinecarbaldehydes. The e.e. of pyridyl alkanol amplified up to 88% e.e. without the need for any other chiral auxiliary.

Design of Chiral Catalysis and Asymmetric Autocatalysis for the Enantioselective Additions of Organozinc Reagents.

Diphenyl(1-methylpyrrolidin-2-yl)methanol (DPMPM) and N, N-dibutylnorephedrine (DBNE) are highly enantio- and chemoselective chiral catalysts for the addition of dialkylzincs to various aldehydes, affording sec-alcohols with high enantiomeric excesses. Heterogeneous chiral catalyst supported on polystyrene is also highly enantioselective. Pyrimidyl and quinolyl alkanols are asymmetric autocatalysts with amplification of enantiomeric excess in the enantioselective isopropylation of aldehydes. Enantioselective addition of dialkylzincs to N-diphenylphosphinylimines and conjugate addition to enones are performed using N, N-dialkylnorephedrines.

Asymmetric autocatalytic reaction of 3-quinolylalkanol with amplification of enantiomeric excess

The enantiomeric excess of a chiral 3-quinolylalkanol increases from 8.9 to 88.1% by a series of asymmetric autocatalytic alkylations of quinoline-3-carbaldehyde using diisopropylzinc.

Dissipative structures and amplification of enantiomeric excess (an experimental point of view)

Various mathematical models have been proposed to account for the origin of chiral molecules in biological systems. Most of these models invoke non-linear phenomena, and are based on the general concept of dissipative structures. These theoretical models define the fundamental criteria which must be obeyed by the experimental systems that we have investigated. Our initial approach to this problem was an extensive search of the literature data in order to select a few systems or experimental situations which would satisfy the criteria defined by the theoretical models. For these reasons, we carried out a study of the possibility of stereospecific autocatalysis in the asymmetric polymerisation of benzofuran. Similarly, the formation of spatial dissipative structures by coupling of a transport process with an interfacial reaction was investigated as a simple experimental example of symmetry breaking.