Breslow intermediate

E601252

The Breslow intermediate is a reactive enaminol species proposed in organocatalysis that explains the umpolung (polarity inversion) of aldehydes in N-heterocyclic carbene-catalyzed reactions.

All labels observed (1)

Label Occurrences
Breslow intermediate canonical 1

How this entity was disambiguated

Statements (47)

Predicate Object
instanceOf enaminol ⓘ
organic chemical species ⓘ
reaction intermediate ⓘ
explains umpolung of aldehydes ⓘ
field organocatalysis ⓘ
physical organic chemistry ⓘ
reaction mechanism analysis ⓘ
formedBy addition of N-heterocyclic carbene to aldehyde carbonyl ⓘ
subsequent proton transfer and tautomerization to an enaminol ⓘ
hasAlternativeName Breslow enaminol ⓘ
NHC-bound enaminol intermediate ⓘ
hasComponent alpha-carbon bearing partial negative character ⓘ
conjugated C=C–C=O system ⓘ
enol hydroxyl group ⓘ
hasElectronicEffect inverts electrophilic carbonyl carbon to nucleophilic center ⓘ
hasPrecursor N-heterocyclic carbene ⓘ
aldehyde ⓘ
hasProperty can be stabilized in some systems for spectroscopic observation ⓘ
highly reactive ⓘ
nucleophilic at the former carbonyl carbon ⓘ
often not directly observable ⓘ
results from polarity inversion of aldehyde carbonyl ⓘ
transient ⓘ
hasRole key intermediate in N-heterocyclic carbene catalysis ⓘ
nucleophilic acyl anion equivalent ⓘ
umpolung reagent ⓘ
isPartOf mechanism of Stetter reaction ⓘ
mechanism of benzoin condensation ⓘ
mechanisticRole central intermediate in organocatalytic umpolung chemistry ⓘ
connects N-heterocyclic carbene addition to aldehyde with acyl anion reactivity ⓘ
namedAfter Ronald Breslow ⓘ
occursIn N-heterocyclic carbene organocatalytic cycles ⓘ
participatesIn N-heterocyclic carbene-catalyzed Stetter reaction ⓘ
N-heterocyclic carbene-catalyzed acylation reactions ⓘ
N-heterocyclic carbene-catalyzed benzoin condensation ⓘ
N-heterocyclic carbene-catalyzed umpolung reactions of aldehydes ⓘ
proposedBy Ronald Breslow ⓘ
proposedIn 1950s ⓘ
relatedTo N-heterocyclic carbene ⓘ
Stetter reaction ⓘ
acyl anion equivalent ⓘ
benzoin condensation ⓘ
umpolung ⓘ
stabilizedBy conjugating substituents on the aldehyde ⓘ
electron-withdrawing substituents on the N-heterocyclic carbene ⓘ
usedAsConceptIn design of new N-heterocyclic carbene catalysts ⓘ
development of umpolung-based synthetic methods ⓘ

How these facts were elicited

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

Ronald Breslow → notableConcept → Breslow intermediate ⓘ