Results 51 to 60 of about 33,103 (197)
Novel Chiral Switching Ligands for Enantioselective Asymmetric Reductions of Prochiral Ketones
Molecules, 2001 The newly developed chiral ligands 1 and 4 show opposite enantioselectivity in the asymmetric reduction of prochiral ketones resulting in the production of either enantiomer depending on the metal complex with high enantiomeric excess.
S. Velmathi +3 more
doaj +1 more source
Inconclusive evidence for nonterrestrial isoleucine enantiomeric excesses in primitive meteorites [PDF]
Proceedings of the National Academy of Sciences, 2012 Pizzarello et al. (1) recently described the soluble organic content of eight Antarctic Renazzo-type (CR) carbonaceous chondrites and reported large enantiomeric excesses (ee) of l-isoleucine and d-alloisoleucine. The reported values of ee decrease with inferred increases in aqueous alteration.
Jamie E, Elsila +4 more
openaire +2 more sources
Chiral symmetry breaking and information accumulation in pre-biological protocell evolution
Scientific ReportsWe study a linear evolutionary model based on the two-dimensional distribution of protocells by total enantiomeric excess and the amount of stored information, which they can pass from generation to generation, and without any mutual inhibition.
Konstantin K. Konstantinov +1 more
doaj +1 more source
, 2012 Experimental mechanisms that yield the growth of homochiral copolymers over their heterochiral counterparts have been advocated by Lahav and co-workers. These chiral amplification mechanisms proceed through racemic {\beta}-sheet-controlled polymerization
Blanco, Celia, Hochberg, David
core +1 more source
Stereo block copolymers of L- and D-lactides [PDF]
, 1990 Sequential diblock copolymers composed of L- and D-lactic acid residues were synthesized through a living ring-opening polymerization of L- and D-lactide initiated by aluminium tris(2-propanolate).
Dijkstra, Pieter J. +2 more
core +3 more sources
Highly Efficient Lipase-Catalyzed Kinetic Resolution of Chiral Amines
CHIMIA, 1994 The lipase Candida antarctica catalyzes the enantioselective acetylation of chiral primary amines, kinetic resolution leading to an enantiomeric excess (ee) of 90–98%.
Manfred T. Reetz, Claus Dreisbach
doaj +2 more sources
, 2008 A generalized autocatalytic model for chiral polymerization is investigated in detail. Apart from enantiomeric cross-inhibition, the model allows for the autogenic (non-catalytic) formation of left and right-handed monomers from a substrate with reaction
A Brandenburg +23 more
core +1 more source
Temporary mirror symmetry breaking and chiral excursions in open and closed systems [PDF]
, 2011 The reversible Frank model is capable of amplifying the initial small statistical deviations from the idealized racemic composition. This temporary amplification can be interpreted as a chiral excursion in a dynamic phase space.
Avetisov +20 more
core +2 more sources
Accurate Determination of Enantiomeric Excess Using Raman Optical Activity
Symmetry, 2022 The optical purity of a chiral sample is of particular importance to the analytical chemistry and pharmaceutical industries. In recent years, the vibrational optical activity (VOA) has become established as a sensitive and nondestructive technique for the analysis of chiral molecules in solution. However, the relatively limited accuracy in the range of
Pavel Michal +5 more
openaire +1 more source
One pot ‘click’ reactions: tandem enantioselective biocatalytic epoxide ring opening and [3+2] azide alkyne cycloaddition [PDF]
, 2010 Halohydrin dehalogenase (HheC) can perform enantioselective azidolysis of aromatic epoxides to 1,2-azido alcohols which are subsequently ligated to alkynes producing chiral hydroxy triazoles in a one-pot procedure with excellent enantiomeric excess.
Campbell-Verduyn, Lachlan S., +6 more
core +3 more sources