Evans auxiliary-based asymmetric synthesis
E634404
Evans auxiliary-based asymmetric synthesis is a widely influential chiral auxiliary strategy developed by David A. Evans that enables highly stereoselective construction of complex molecules in organic synthesis.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Evans auxiliary-based asymmetric synthesis canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T6995010 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
Target entity: Evans auxiliary-based asymmetric synthesis Context triple: [David A. Evans, notableWork, Evans auxiliary-based asymmetric synthesis]
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A.
Enantioselective Chemical Synthesis
Enantioselective Chemical Synthesis is a foundational work in organic chemistry that systematically presents strategies and methods for constructing chiral molecules with high stereocontrol.
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B.
Trost asymmetric allylic alkylation
Trost asymmetric allylic alkylation is a palladium-catalyzed enantioselective carbon–carbon bond-forming reaction that enables the synthesis of chiral molecules from prochiral allylic substrates.
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C.
Sharpless asymmetric dihydroxylation
Sharpless asymmetric dihydroxylation is a landmark chemical reaction that uses chiral catalysts to add two hydroxyl groups across an alkene with high enantioselectivity, revolutionizing asymmetric synthesis in organic chemistry.
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D.
Breslow intermediate in organocatalysis
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.
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E.
Corey–Nicolaou macrolactonization
Corey–Nicolaou macrolactonization is a widely used organic synthesis reaction that forms large-ring lactones from hydroxy acids via an activated ester intermediate.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
Target entity: Evans auxiliary-based asymmetric synthesis Target entity description: Evans auxiliary-based asymmetric synthesis is a widely influential chiral auxiliary strategy developed by David A. Evans that enables highly stereoselective construction of complex molecules in organic synthesis.
-
A.
Enantioselective Chemical Synthesis
Enantioselective Chemical Synthesis is a foundational work in organic chemistry that systematically presents strategies and methods for constructing chiral molecules with high stereocontrol.
-
B.
Trost asymmetric allylic alkylation
Trost asymmetric allylic alkylation is a palladium-catalyzed enantioselective carbon–carbon bond-forming reaction that enables the synthesis of chiral molecules from prochiral allylic substrates.
-
C.
Sharpless asymmetric dihydroxylation
Sharpless asymmetric dihydroxylation is a landmark chemical reaction that uses chiral catalysts to add two hydroxyl groups across an alkene with high enantioselectivity, revolutionizing asymmetric synthesis in organic chemistry.
-
D.
Breslow intermediate in organocatalysis
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.
-
E.
Corey–Nicolaou macrolactonization
Corey–Nicolaou macrolactonization is a widely used organic synthesis reaction that forms large-ring lactones from hydroxy acids via an activated ester intermediate.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
asymmetric synthesis strategy
ⓘ
chiral auxiliary methodology ⓘ stereoselective synthesis method ⓘ |
| advantage |
auxiliary can be removed after stereocenter formation
ⓘ
auxiliary can often be recovered and reused ⓘ |
| appliedIn |
complex molecule construction
ⓘ
pharmaceutical synthesis ⓘ total synthesis of natural products ⓘ |
| basedOn | chiral N-acyl oxazolidinone auxiliaries ⓘ |
| contrastsWith | catalytic asymmetric synthesis ⓘ |
| controls | relative configuration of newly formed stereocenters ⓘ |
| developedBy | David A. Evans NERFINISHED ⓘ |
| enables | highly stereoselective construction of complex molecules ⓘ |
| field |
organic chemistry
ⓘ
synthetic organic chemistry ⓘ |
| followedBy | auxiliary cleavage to reveal enantiomerically enriched products ⓘ |
| historicalImpact | popularized chiral auxiliary approach in asymmetric synthesis ⓘ |
| influenced | development of other chiral auxiliary systems ⓘ |
| involves |
diastereoselective bond formation
ⓘ
enolization under basic conditions ⓘ formation of N-acyl imides ⓘ |
| keyIntermediate | chiral metal enolate ⓘ |
| keyTransformation | diastereoselective Michael addition ⓘ |
| keyTransformation |
diastereoselective acylation
ⓘ
diastereoselective conjugate addition ⓘ |
| keyTransformation | diastereoselective aldol reaction ⓘ |
| keyTransformation | diastereoselective enolate alkylation ⓘ |
| namedAfter | David A. Evans NERFINISHED ⓘ |
| optimizationParameter |
choice of base and metal counterion
ⓘ
temperature control for stereoselectivity ⓘ |
| provides |
high diastereoselectivity
ⓘ
predictable stereochemical outcome ⓘ |
| reliesOn |
chelation-controlled transition states
ⓘ
diastereofacial differentiation of enolates ⓘ |
| requires | stoichiometric amount of chiral auxiliary ⓘ |
| stereochemicalOutcome | products with high enantiomeric excess after auxiliary removal ⓘ |
| stereocontrolOrigin | chiral environment of the oxazolidinone ring ⓘ |
| strategyType | substrate-controlled stereoselective synthesis ⓘ |
| timePeriodOfDevelopment |
1980s
ⓘ
late 1970s ⓘ |
| typicalAuxiliaryBackbone | oxazolidinone derived from amino alcohols ⓘ |
| typicalMetalCounterion |
boron
ⓘ
lithium ⓘ titanium ⓘ |
| typicalSubstrateClass | chiral N-acyl oxazolidinones ⓘ |
| usedFor |
construction of contiguous stereocenters
ⓘ
construction of quaternary stereocenters ⓘ |
| uses |
Evans chiral auxiliary
NERFINISHED
ⓘ
N-acyloxazolidinone chiral auxiliaries ⓘ |
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Subject: Evans auxiliary-based asymmetric synthesis Description of subject: Evans auxiliary-based asymmetric synthesis is a widely influential chiral auxiliary strategy developed by David A. Evans that enables highly stereoselective construction of complex molecules in organic synthesis.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.