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Enantiomeric separation
Enantiomeric separation is a class of analytical chemistry methods, mostly chromatographic or electrophoretic, that resolves a racemic mixture into its enantiomers so a chiral compound's composition can be measured.
Enantiopure drugs
Enantiopure drugs are pharmaceuticals consisting of a single enantiomer of a chiral molecule rather than a racemate, exemplified by escitalopram and esomeprazole and produced by chiral synthesis or resolution.
Enantioselective [2+2] photocycloaddition
The enantioselective [2+2] photocycloaddition is a light-driven reaction joining two alkenes into a cyclobutane ring, where a chiral catalyst or sensitizer selects which enantiomer predominates.
Enantioselective atom-transfer radical addition
Enantioselective atom-transfer radical addition is a class of radical reactions in which a radical adds to an alkene and a chiral catalyst sets the stereochemistry.
Enantioselective C–H activation
Enantioselective C–H activation is a class of catalytic reactions in which a transition metal cleaves a carbon–hydrogen bond of a prochiral substrate, producing one enantiomer preferentially.
Enantioselective C–H activation with MPAA ligands
Enantioselective C–H activation with MPAA ligands is a palladium-catalyzed strategy introduced by Jin-Quan Yu's group at Scripps Research in 2008, where chiral amino acid ligands deliver up to 99% ee.
Enantioselective C–H amidation
Enantioselective C–H amidation is a class of catalytic reactions converting carbon–hydrogen bonds directly into chiral amides, a field that emerged as a distinct area around 2019.
Enantioselective C–H amination
Enantioselective C–H amination is the catalytic conversion of a C–H bond into a C–N bond in a way that favors one enantiomer, giving optically enriched chiral amines from hydrocarbons without pre-installed leaving groups.
Enantioselective C–H borylation
Enantioselective C–H borylation is a class of catalytic reactions replacing a carbon–hydrogen bond with a carbon–boron bond while favoring one enantiomer of the chiral organoboronate product.
Enantioselective fluorination
Enantioselective fluorination, also called asymmetric fluorination, uses catalytic methods to add fluorine to achiral substrates so one enantiomer forms preferentially, supplying chiral building blocks for pharmaceuticals.
Enantioselective Minisci reaction
The enantioselective Minisci reaction is an asymmetric variant of the Minisci reaction, first made catalytic in 2018 at Cambridge, that adds carbon radicals to basic heteroarenes enantioselectively.
Enantioselective photoredox catalysis
Enantioselective photoredox catalysis is a family of organic synthesis methods in which a visible-light photoredox catalyst makes radical intermediates while a chiral catalyst sets the product's stereochemistry.
Enantioselective synthesis
Enantioselective synthesis, also called asymmetric synthesis, is chemical synthesis that produces one enantiomer of a chiral molecule in preference over its mirror image, measured by enantiomeric excess.
Enantioselective triplet energy transfer photocatalysis
Enantioselective triplet energy transfer photocatalysis is a strategy in organic synthesis in which a chiral photosensitizer transfers triplet energy from absorbed visible light to a bound substrate, yielding one enantiomer selectively.
Enantioselective triplet-sensitized [2+2] cycloadditions
Enantioselective triplet-sensitized [2+2] cycloadditions are photochemical reactions in which a photosensitizer transfers triplet energy to an alkene, with a chiral sensitizer or chiral catalyst imposing enantioselectivity.
Enantioselectivity
Enantioselectivity is the preferential formation of one enantiomer over another in a chemical reaction, measured by enantiomeric excess; high enantioselective catalysis typically means over 90% ee.
Enantiospecific sp3–sp3 cross-coupling of boronic esters
Enantiospecific sp3–sp3 cross-coupling of boronic esters is a family of reactions joining enantioenriched alkyl boronic esters to another sp3 carbon partner while transferring the stereocenter's configuration into the product.
Enantiotopic
Enantiotopic describes constitutionally identical atoms, groups, or faces in a molecule related only by mirror-type symmetry, where replacing one member gives one enantiomer and replacing the other gives its mirror image.
Encapsulated graphene with ballistic transport
Encapsulated graphene with ballistic transport is graphene sandwiched between hexagonal boron nitride layers, which isolate it so electrons cross whole devices without scattering, even at room temperature.
Enceladus
Enceladus is an icy moon of Saturn, about 310 miles across, that vents water vapor and ice into space from a global ocean beneath its ice shell.
End-group analysis
End-group analysis is an analytical chemistry method that determines a polymer's number-average molar mass by measuring the concentration of chemical groups at the ends of its chains.
Enders A. Robinson
Enders A. Robinson, full name Enders Anthony Robinson, was an American geophysicist known as the father of digital geophysics, who pioneered digital seismic data processing for oil exploration.
Enders Anthony Robinson
Enders Anthony Robinson was an American geophysicist who pioneered digital seismic data processing, establishing predictive deconvolution for oil exploration, and was elected to the National Academy of Engineering in 1988.
ENDF/B
ENDF/B (Evaluated Nuclear Data File, Part B) is the United States' recommended library of evaluated nuclear reaction data, produced by CSEWG and maintained at Brookhaven National Laboratory.
Endmember extraction
Endmember extraction is a hyperspectral image analysis method that identifies the pure spectral signatures of materials in a scene, the first step of spectral unmixing.
Endohedral fullerene
An endohedral fullerene is a fullerene molecule, a closed hollow cage of carbon atoms, with an atom, ion, or molecule trapped inside its cavity, first observed in 1985 shortly after the discovery of C₆₀ itself.
Endomorphism
An endomorphism is a structure-preserving map from a mathematical object to itself, defined for groups, modules, rings, and vector spaces; in linear algebra it is a linear map from a space to itself.
Endomorphism ring
The endomorphism ring, also called the endomorphism algebra, is the ring formed by all homomorphisms from a mathematical object to itself, with composition of maps as multiplication.
Endostatin
Endostatin is a 20-kDa C-terminal fragment of type XVIII collagen that inhibits angiogenesis and tumor growth, identified in 1997 in Folkman's laboratory; a modified version, Endostar, is approved in China.
Endosulfan
Endosulfan is an organochlorine insecticide of the cyclodiene type, developed in Germany in 1954 and used widely on crops before being phased out globally under the Stockholm Convention.