Breslow intermediate in organocatalysis
E601249
The Breslow intermediate in organocatalysis is a transient nucleophilic carbene-derived species central to thiamine- and N-heterocyclic carbene-catalyzed umpolung reactions of carbonyl compounds.
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
carbene-derived species
ⓘ
nucleophilic carbene intermediate ⓘ reaction intermediate ⓘ |
| enables | nucleophilic reactivity at the former carbonyl carbon ⓘ |
| hasBeen | characterized by spectroscopic methods in some systems ⓘ |
| hasChemicalNature |
carbene-derived
ⓘ
nucleophilic ⓘ |
| hasElectronicCharacter |
acyl anion equivalent
ⓘ
enaminol-like ⓘ zwitterionic ⓘ |
| hasFunctionalGroupFeatures |
alpha-hydroxyalkyl substituent on carbene center
ⓘ
conjugated C=C–O system ⓘ |
| hasPrecursor |
N-heterocyclic carbene catalyst
ⓘ
aldehyde substrate ⓘ carbonyl compound ⓘ thiamine-derived carbene ⓘ |
| hasRole |
key intermediate in organocatalysis
ⓘ
umpolung reagent ⓘ |
| hasStability | short-lived ⓘ |
| isAssociatedWith |
biomimetic NHC catalysis
ⓘ
thiamine pyrophosphate catalysis ⓘ |
| isCentralTo |
N-heterocyclic carbene-catalyzed umpolung reactions
ⓘ
thiamine-catalyzed umpolung reactions ⓘ |
| isDerivedFrom |
N-heterocyclic carbene
ⓘ
thiazolium carbene ⓘ |
| isDifficultTo | isolate ⓘ |
| isDiscussedIn |
organocatalysis literature
ⓘ
physical organic chemistry of carbenes ⓘ |
| isFormedBy |
addition of carbene to carbonyl carbon
ⓘ
proton transfer from carbonyl carbon to carbene center ⓘ |
| isImportantFor |
design of NHC catalysts
ⓘ
understanding thiamine-dependent enzymatic mechanisms ⓘ |
| isKeyTo | reversal of polarity at the carbonyl carbon ⓘ |
| isNamedAfter | Ronald Breslow NERFINISHED ⓘ |
| isOften | observed indirectly ⓘ |
| isTransient | true ⓘ |
| isUsedIn |
organocatalytic C–C bond formation
ⓘ
organocatalytic acylation reactions ⓘ |
| participatesIn |
NHC-catalyzed acyl anion equivalent chemistry
ⓘ
Stetter reaction NERFINISHED ⓘ benzoin condensation ⓘ umpolung of carbonyl compounds ⓘ |
| reactsWith |
Michael acceptors
ⓘ
electrophilic carbonyl compounds ⓘ |
| wasProposedBy | Ronald Breslow NERFINISHED ⓘ |
| wasProposedIn | 1958 ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.