Journal of the American Chemical Society
DFG)ꢀforꢀpost-doctoralꢀfellowshipsꢀandꢀH.-H.L.ꢀthanksꢀtheꢀMin-
Page 8 of 10
(
lylationꢀ ofꢀ Aldehydes:ꢀ Aꢀ Catalyticꢀ Enantioselectiveꢀ Aza-Copeꢀ Rear-
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
istryꢀofꢀScienceꢀandꢀTechnologyꢀofꢀtheꢀRepublicꢀofꢀChinaꢀ(MOSTꢀ
106-2917-I-003-0040).ꢀ Theꢀ supportꢀ andꢀ resourcesꢀ fromꢀ theꢀ
CenterꢀforꢀHighꢀPerformanceꢀComputingꢀatꢀtheꢀUniversityꢀofꢀ
Utahꢀareꢀgratefullyꢀacknowledged.ꢀFurtherꢀcomputationalꢀre-
sourcesꢀwereꢀprovidedꢀbyꢀtheꢀExtremeꢀScienceꢀandꢀEngineer-
ingꢀDiscoveryꢀEnvironmentꢀ(XSEDE),ꢀwhichꢀisꢀsupportedꢀbyꢀtheꢀ
NSFꢀ (ACI-1548562)ꢀ andꢀ providedꢀ throughꢀ allocationꢀ TG-
CHE180003.ꢀꢀ
rangement.ꢀAngew.ꢀChem.ꢀInt.ꢀEd.ꢀ2008,ꢀ47,ꢀ10090–10093.ꢀ(l)ꢀMaity,ꢀP.;ꢀ
Pemberton,ꢀR.ꢀP.;ꢀTantillo,ꢀD.ꢀJ.;ꢀTambar,ꢀU.ꢀK.ꢀBrønstedꢀAcidꢀCatalyzedꢀ
Enantioselectiveꢀ Indoleꢀ Aza-Claisenꢀ Rearrangementꢀ Mediatedꢀ byꢀ anꢀ
AreneꢀCH–OꢀInteraction.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2013,ꢀ135,ꢀ16380–16383.ꢀ
(m)ꢀRehbein,ꢀJ.;ꢀHiersemann,ꢀM.,ꢀGosteli-ClaisenꢀRearrangement:ꢀDFTꢀ
StudyꢀofꢀSubstituent-RateꢀEffects.ꢀJ.ꢀOrg.ꢀChem.ꢀ2009,ꢀ74,ꢀ4336–4342.ꢀ
(n)ꢀRehbein,ꢀJ.;ꢀLeick,ꢀS.;ꢀHiersemann,ꢀM.,ꢀGosteli-ClaisenꢀRearrange-
ment:ꢀ Substrateꢀ Synthesis,ꢀ Simpleꢀ Diastereoselectivity,ꢀ andꢀ Kineticꢀ
Studies.ꢀJ.ꢀOrg.ꢀChem.ꢀ2009,ꢀ74,ꢀ1531–1540.ꢀ(o)ꢀTroendlin,ꢀJ.;ꢀRehbein,ꢀ
J.;ꢀHiersemann,ꢀM.;ꢀTrapp,ꢀO.,ꢀIntegrationꢀofꢀCatalysisꢀandꢀAnalysisꢀisꢀtheꢀ
Keyꢀ -ꢀ Rapidꢀ andꢀ Preciseꢀ Investigationꢀ ofꢀ theꢀ Catalyticꢀ Asymmetricꢀ
Gosteli-ClaisenꢀRearrangement.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2011,ꢀ133,ꢀ16444–
16450.ꢀ
(4) (a)ꢀLambert,ꢀT.ꢀH.;ꢀMacMillan,ꢀD.ꢀW.ꢀC.ꢀDevelopmentꢀofꢀaꢀNewꢀ
Lewisꢀ Acid-Catalyzedꢀ [3,3]-Sigmatropicꢀ Rearrangement:ꢀ Theꢀ Alleno-
ate-ClaisenꢀRearrangement.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2002,ꢀ124,ꢀ13646–13647.ꢀ
(b)Lambert,ꢀT.ꢀH.ꢀDevelopmentꢀofꢀtheꢀLewisꢀAcidꢀCatalyzedꢀAllenoate-
ClaisenꢀRearrangement.ꢀInvestigationsꢀofꢀEnantioselectiveꢀCatalysisꢀofꢀ
theꢀAllenoate-ClaisenꢀRearrangement.ꢀStudiesꢀTowardsꢀtheꢀTotalꢀSyn-
thesisꢀofꢀErythrolideꢀE.,ꢀPh.D.ꢀDissertation,ꢀCaliforniaꢀInstituteꢀofꢀTech-
nology,ꢀPasadena,ꢀCA,ꢀ2004.ꢀ(c)ꢀLopes,ꢀS.ꢀM.ꢀM.;ꢀSantos,ꢀB.ꢀS.;ꢀPalacios,ꢀ
F.;ꢀPinhoꢀEꢀMelo,ꢀT.ꢀM.ꢀV.ꢀD.ꢀMicrowave-assistedꢀReactionsꢀofꢀAllenicꢀes-
ters:ꢀ[3+2]ꢀAnellationsꢀandꢀAllenoate-ClaisenꢀRearrangement.ꢀArkivocꢀ
2010,ꢀ2010,ꢀ70–81.ꢀ
(5) ꢀ(a)ꢀPhipps,ꢀR.ꢀJ.;ꢀHamilton,ꢀG.ꢀL.;ꢀToste,ꢀF.ꢀD.ꢀTheꢀprogressionꢀofꢀ
chiralꢀ anionsꢀ fromꢀ conceptsꢀ toꢀ applicationsꢀ inꢀ asymmetricꢀ catalysis.ꢀ
Nat.ꢀ Chem.ꢀ 2012,ꢀ 4,ꢀ 603–614.ꢀ (b)ꢀ Parmar,ꢀ D.;ꢀ Sugiono,ꢀ E.;ꢀ Raja,ꢀ S.;ꢀ
Rueping,ꢀM.ꢀCompleteꢀFieldꢀGuideꢀtoꢀAsymmetricꢀBINOL-PhosphateꢀDe-
rivedꢀBrønstedꢀAcidꢀandꢀMetalꢀCatalysis:ꢀHistoryꢀandꢀClassificationꢀbyꢀ
ModeꢀofꢀActivation;ꢀBrønstedꢀAcidity,ꢀHydrogenꢀBonding,ꢀIonꢀPairing,ꢀ
andꢀMetalꢀPhosphates.ꢀChem.ꢀRev.ꢀ2014,ꢀ114,ꢀ9047–9153.ꢀ
(6) (a)ꢀGuo,ꢀQ.-S.;ꢀDu,ꢀD.-M.;ꢀXu,ꢀJ.ꢀTheꢀDevelopmentꢀofꢀDoubleꢀAxiallyꢀ
ChiralꢀPhosphoricꢀAcidsꢀandꢀTheirꢀCatalyticꢀTransferꢀHydrogenationꢀofꢀ
Quinolines.ꢀ Angew.ꢀ Chem.ꢀ Int.ꢀ Ed.ꢀ 2008,ꢀ 47,ꢀ 759–762.ꢀ (b)ꢀ Honjo,ꢀ T.;ꢀ
Phipps,ꢀR.ꢀJ.;ꢀRauniyar,ꢀV.;ꢀToste,ꢀF.ꢀD.ꢀAꢀDoublyꢀAxiallyꢀChiralꢀPhos-
phoricꢀAcidꢀCatalystꢀforꢀtheꢀAsymmetricꢀTandemꢀOxyfluorinationꢀofꢀEn-
amides.ꢀAngew.ꢀChem.ꢀInt.ꢀEd.ꢀ2012,ꢀ51,ꢀ9684–9688.ꢀ(c)ꢀHiramatsu,ꢀK.;ꢀ
Honjo,ꢀ T.;ꢀ Rauniyar,ꢀ V.;ꢀ Toste,ꢀ F.ꢀ D.ꢀ Enantioselectiveꢀ Synthesisꢀ ofꢀ
Fluoro-Dihydroquinazolonesꢀandꢀ–BenzooxazinonesꢀbyꢀFluorination-
InitiatedꢀAsymmetricꢀCyclizationꢀReactions.ꢀACSꢀCatal.ꢀ2016,ꢀ6,ꢀ151–
154.ꢀ
REFERENCES
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
(
1) (a)ꢀHiersemann,ꢀM.;ꢀNubbemeyer,ꢀU.ꢀTheꢀClaisenꢀRearrangement:ꢀ
Methodsꢀ andꢀ Applications,ꢀ 1stꢀ ed.;ꢀ Wiley-VCH,ꢀ 2007.ꢀ (b)ꢀ Jones,ꢀ A.ꢀ C.;ꢀ
May,ꢀJ.ꢀA.;ꢀSarpong,ꢀR.;ꢀStoltz,ꢀB.ꢀM.ꢀTowardꢀaꢀSymphonyꢀofꢀReactivity:ꢀ
CascadesꢀInvolvingꢀCatalysisꢀandꢀSigmatropicꢀRearrangements.ꢀAngew.ꢀ
Chem.ꢀInt.ꢀEd.ꢀ2014,ꢀ53,ꢀ2556–2591.ꢀ(c)ꢀMajumdar,ꢀK.ꢀC.;ꢀAlam,ꢀS.;ꢀChat-
topadhyay,ꢀ B.ꢀ Catalysisꢀ ofꢀ theꢀ Claisenꢀ Rearrangement.ꢀ Tetrahedronꢀ
2008,ꢀ64,ꢀ597–643.ꢀ(d)ꢀCastro,ꢀA.ꢀM.ꢀM.ꢀClaisenꢀRearrangementꢀoverꢀtheꢀ
PastꢀNineꢀDecades.ꢀChem.ꢀRev.ꢀ2004,ꢀ104,ꢀ2939–3002.ꢀ(e)ꢀGonda,ꢀJ.ꢀTheꢀ
Belluš-Claisenꢀrearrangement.ꢀAngew.ꢀChem.ꢀInt.ꢀEd.ꢀ2004,ꢀ43,ꢀ3516–
3
524.ꢀ
(2) (a)ꢀ Kadam,ꢀ V.ꢀ D.;ꢀ Raoꢀ B.,ꢀ S.ꢀ S.;ꢀ Mahesh,ꢀ S.ꢀ K.;ꢀ Chakraborty,ꢀ M.;ꢀ
Vemulapalli,ꢀS.ꢀP.ꢀB.;ꢀDayaka,ꢀS.ꢀN.;ꢀSudhakar,ꢀG.ꢀStereoselectiveꢀAccessꢀ
toꢀtheꢀCoreꢀStructureꢀofꢀMacroline-TypeꢀIndoleꢀAlkaloids:ꢀTotalꢀSynthe-
sisꢀofꢀMacrolineꢀandꢀAlstomicine.ꢀOrg.ꢀLett.ꢀ2018,ꢀ20,4782–4786.ꢀ(b)ꢀ
Crimmins,ꢀM.ꢀT.;ꢀKnight,ꢀJ.ꢀD.;ꢀWilliams,ꢀP.ꢀS.;ꢀZhang,ꢀY.ꢀStereoselectiveꢀ
SynthesisꢀofꢀQuaternaryꢀCarbonsꢀviaꢀtheꢀDianionicꢀIreland-ClaisenꢀRe-
arrangement.ꢀOrg.ꢀLett.ꢀ2014,ꢀ16,2458–2461.ꢀ(c)ꢀPeng,ꢀB.;ꢀGeerdink,ꢀD.;ꢀ
Maulide,ꢀN.ꢀElectrophilicꢀRearrangementsꢀofꢀChiralꢀAmides:ꢀAꢀTracelessꢀ
Asymmetricꢀα-Allylation.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2013,ꢀ135,ꢀ14968–14971.ꢀ
(
d)ꢀ Takao,ꢀ K.;ꢀ Sakamoto,ꢀ S.;ꢀ Touati,ꢀ M.ꢀ A.;ꢀ Kusakawa,ꢀ Y.;ꢀ Tadano,ꢀ K.ꢀ
AsymmetricꢀConstructionꢀofꢀAll-CarbonꢀQuaternaryꢀStereocentersꢀbyꢀ
Chiral-Auxiliary-MediatedꢀClaisenꢀRearrangementꢀandꢀTotalꢀSynthesisꢀ
ofꢀ(+)-Bakuchiol.ꢀMoleculesꢀ2012,ꢀ17,ꢀ13330–13344.ꢀ(e)ꢀLiu,ꢀZ.;ꢀMehta,ꢀ
S.ꢀJ.;ꢀLee,ꢀK.-S.;ꢀGrossman,ꢀB.;ꢀQu,ꢀH.;ꢀQu,ꢀX.;ꢀNichol,ꢀG.ꢀS.;ꢀHruby,ꢀV.ꢀJ.ꢀThio-
ClaisenꢀRearrangementꢀUsedꢀinꢀPreparingꢀAnti-β-Functionalizedꢀγ,δ-
UnsaturatedꢀAminoꢀAcids:ꢀScopeꢀandꢀLimitations.ꢀJ.ꢀOrg.ꢀChem.ꢀ2012,ꢀ
7
7,ꢀ1289–1300.ꢀ(f)ꢀQu,ꢀH.;ꢀGu,ꢀX.;ꢀLiu,ꢀZ.;ꢀMin,ꢀB.ꢀJ.;ꢀHruby,ꢀV.ꢀJ.ꢀAsymmet-
ricꢀ Eschenmoser-Claisenꢀ Rearrangementꢀ forꢀ Anti-β-Substitutedꢀ γ,δ-
UnsaturatedꢀAminoꢀAcids.ꢀOrg.ꢀLett.ꢀ2007,ꢀ9,ꢀ3997–4000.ꢀꢀ
(3) (a)ꢀYoon,ꢀT.ꢀP.;ꢀMacMillan,ꢀD.ꢀW.ꢀC.ꢀEnantioselectiveꢀclaisenꢀrear-
rangements:ꢀ Developmentꢀ ofꢀ aꢀ first-generationꢀ asymmetricꢀ acyl-
Claisenꢀreaction.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2001,ꢀ123,ꢀ2911–2912.ꢀ(b)ꢀAbraham,ꢀ
L.;ꢀ Czerwonka,ꢀ R.;ꢀ Hiersemann,ꢀ M.ꢀ Theꢀ Catalyticꢀ Enantioselectiveꢀ
ClaisenꢀRearrangementꢀofꢀanꢀAllylꢀVinylꢀEther.ꢀAngew.ꢀChem.ꢀInt.ꢀEd.ꢀ
(7) ReviewsꢀonꢀtheꢀroleꢀofꢀNCIsꢀinꢀasymmetricꢀcatalysis:ꢀ(a)ꢀKnowles,ꢀ
R.ꢀR.;ꢀJacobsen,ꢀE.ꢀN.ꢀAttractiveꢀnoncovalentꢀinteractionsꢀinꢀasymmetricꢀ
catalysis:ꢀLinksꢀbetweenꢀenzymesꢀandꢀsmallꢀmoleculeꢀcatalysts.ꢀProc.ꢀ
Natl.ꢀAcad.ꢀSci.ꢀ2010,ꢀ107,ꢀ20678–20685.ꢀ(b)ꢀToste,ꢀF.ꢀD.;ꢀSigman,ꢀM.ꢀS.;ꢀ
Miller,ꢀS.ꢀJ.ꢀPursuitꢀofꢀNoncovalentꢀInteractionsꢀforꢀStrategicꢀSite-Selec-
tiveꢀCatalysis.ꢀAcc.ꢀChem.ꢀRes.ꢀ2017,ꢀ50,ꢀ609–615.ꢀ(c)ꢀNeel,ꢀA.ꢀJ.;ꢀHilton,ꢀ
M.ꢀJ.;ꢀSigman,ꢀM.ꢀS.;ꢀToste,ꢀF.ꢀD.ꢀExploitingꢀnon-covalentꢀπꢀinteractionsꢀ
forꢀcatalystꢀdesign.ꢀNatureꢀ2017,ꢀ543,ꢀ637–646.ꢀꢀ
2
001,ꢀ40,ꢀ4700–4703.ꢀ(c)ꢀLinton,ꢀE.ꢀC.;ꢀKozlowski,ꢀM.ꢀC.ꢀCatalyticꢀEnan-
tioselectiveꢀ Meerwein-Eschenmoserꢀ Claisenꢀ Rearrangement:ꢀ Asym-
metricꢀSynthesisꢀofꢀAllylꢀOxindoles.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2008,ꢀ130,ꢀ16162–
1
6163.ꢀ(d)ꢀGeherty,ꢀM.ꢀE.;ꢀDura,ꢀR.ꢀD.;ꢀNelson,ꢀS.ꢀG.ꢀCatalyticꢀAsymmetricꢀ
(8) Controlꢀexperimentsꢀrevealedꢀthatꢀtheꢀdesiredꢀproductꢀisꢀformedꢀ
inꢀtheꢀabsenceꢀofꢀtheꢀchiralꢀphosphoricꢀacidꢀinꢀmoderateꢀyields.ꢀ
(9) γ-Aryl-substitutedꢀallenicꢀaryl-ꢀandꢀtrifluoroethanol-derivedꢀes-
tersꢀappearedꢀtoꢀbeꢀhighlyꢀunstable.ꢀAttemptsꢀtoꢀreactꢀthemꢀimmedi-
atelyꢀafterꢀisolationꢀprovidedꢀintractableꢀmixturesꢀofꢀproducts.ꢀFurtherꢀ
limitationsꢀinherentꢀtoꢀthisꢀreactionꢀareꢀdiscussedꢀinꢀreferenceꢀ4b.ꢀ
(10) Selectedꢀexamplesꢀforꢀtheꢀuseꢀofꢀcomputationalꢀchemistryꢀtoꢀ
gainꢀ insightꢀ onꢀ reactionꢀ mechanismsꢀ ofꢀ chiralꢀ phosphoricꢀ acidꢀ cata-
lysts:ꢀ(a)ꢀMaji,ꢀR.;ꢀMallojjala,ꢀS.ꢀC.;ꢀWheeler,ꢀS.ꢀE.ꢀChiralꢀphosphoricꢀacidꢀ
catalysis:ꢀfromꢀnumbersꢀtoꢀinsights.ꢀChem.ꢀSoc.ꢀRev.ꢀ2018,ꢀ47,ꢀ1142–
1158ꢀandꢀreferencesꢀtherein.ꢀ(b)ꢀMilo,ꢀA.;ꢀNeel,ꢀA.ꢀJ.;ꢀToste,ꢀF.ꢀD.;ꢀSigman,ꢀ
M.ꢀS.ꢀAꢀdata-intensiveꢀapproachꢀtoꢀmechanisticꢀelucidationꢀappliedꢀtoꢀ
chiralꢀanionꢀcatalysis.ꢀScienceꢀ2015,ꢀ347,ꢀ737–743.ꢀ(c)ꢀReid,ꢀJ.ꢀP.;ꢀGood-
man,ꢀJ.ꢀM.ꢀGoldilocksꢀCatalysts:ꢀComputationalꢀInsightsꢀintoꢀtheꢀRoleꢀofꢀ
theꢀ3,3′ꢀSubstituentsꢀonꢀtheꢀSelectivityꢀofꢀBINOL-DerivedꢀPhosphoricꢀ
AcidꢀCatalysts.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2016,ꢀ138,ꢀ7910–7917.ꢀ(d)ꢀMaji,ꢀR.;ꢀ
Champagne,ꢀP.ꢀA.;ꢀHouk,ꢀK.ꢀN.;ꢀWheeler,ꢀS.ꢀE.ꢀActivationꢀmodeꢀandꢀoriginꢀ
ofꢀselectivityꢀinꢀchiralꢀphosphoricꢀacid-catalyzedꢀoxacycleꢀformationꢀbyꢀ
intramolecularꢀoxetaneꢀdesymmetrizations.ꢀACSꢀCatal.ꢀ2017,ꢀ7,ꢀ7332–
7339.ꢀ(e)ꢀSimón,ꢀL.;ꢀPaton,ꢀR.ꢀS.ꢀTheꢀTrueꢀCatalystꢀRevealed:ꢀTheꢀInter-
ventionꢀofꢀChiralꢀCaꢀandꢀMgꢀPhosphatesꢀinꢀBrønstedꢀAcidꢀPromotedꢀ
Asymmetricꢀ Mannichꢀ Reactions.ꢀ J.ꢀ Am.ꢀ Chem.ꢀ Soc.ꢀ 2018,ꢀ 140,ꢀ 5412–
5420.ꢀ(f)ꢀZhang,ꢀJ.;ꢀYu,ꢀP.;ꢀLi,ꢀS.-Y.;ꢀSun,ꢀH.;ꢀXiang,ꢀS.-H.;ꢀWang,ꢀJ.ꢀ(Joelle);ꢀ
Houk,ꢀK.ꢀN.;ꢀTan,ꢀB.ꢀAsymmetricꢀphosphoricꢀacid–catalyzedꢀfour-com-
ponentꢀUgiꢀreaction.ꢀScienceꢀ2018,ꢀ361,ꢀeaas8707.ꢀ
ClaisenꢀRearrangementꢀofꢀUnactivatedꢀAllylꢀVinylꢀEthers.ꢀJ.ꢀAm.ꢀChem.ꢀ
Soc.ꢀ2010,ꢀ132,ꢀ11875–11877.ꢀ(e)ꢀTan,ꢀJ.;ꢀCheon,ꢀC.-H.;ꢀYamamoto,ꢀH.ꢀ
Catalyticꢀ Asymmetricꢀ Claisenꢀ Rearrangementꢀ ofꢀ Enolphosphonates:ꢀ
Constructionꢀ ofꢀ Vicinalꢀ Tertiaryꢀ andꢀ All-Carbonꢀ Quaternaryꢀ Centers.ꢀ
Angew.ꢀChem.ꢀInt.ꢀEd.ꢀ2012,ꢀ51,ꢀ8264–8267.ꢀ(f)ꢀBecker,ꢀJ.;ꢀButt,ꢀL.;ꢀvonꢀ
Kiedrowski,ꢀ V.;ꢀ Mischler,ꢀ E.;ꢀ Quentin,ꢀ F.;ꢀ Hiersemann,ꢀ M.ꢀ Catalyticꢀ
AsymmetricꢀClaisenꢀRearrangementꢀofꢀGosteli-TypeꢀAllylꢀVinylꢀEthers:ꢀ
Totalꢀ Synthesisꢀ ofꢀ (-)-9,10-Dihydroecklonialactoneꢀ B.ꢀ J.ꢀ Org.ꢀ Chem.ꢀ
2
014,ꢀ79,ꢀ3040–3051.ꢀ(g)ꢀFontouraꢀRodrigues,ꢀT.ꢀC.ꢀA.;ꢀAlvesꢀSilva,ꢀW.;ꢀ
LiraꢀMachado,ꢀA.ꢀH.ꢀRecentꢀAdvancesꢀinꢀtheꢀAsymmetricꢀClaisenꢀRear-
rangementꢀPromotedꢀbyꢀChiralꢀOrganometallicꢀLewisꢀAcidsꢀorꢀOrganicꢀ
Brønsted-Lowryꢀ Acids.ꢀ Currentꢀ Org.ꢀ Synth.ꢀ 2015,ꢀ 12,ꢀ 795–805.ꢀ (h)ꢀ
Zheng,ꢀH.;ꢀWang,ꢀY.;ꢀXu,ꢀC.;ꢀXu,ꢀX.;ꢀLin,ꢀL.;ꢀLiu,ꢀX.;ꢀFeng,ꢀX.ꢀStereodivergentꢀ
SynthesisꢀofꢀVicinalꢀQuaternary-QuaternaryꢀStereocentersꢀandꢀBioac-
tiveꢀHyperolactones.ꢀNat.ꢀCommun.ꢀ2018,ꢀ9,ꢀ1968.ꢀAlternatively,ꢀguan-
idiniumꢀsalts,ꢀN-heterocyclicꢀcarbenesꢀandꢀphosphoricꢀacidsꢀcanꢀalsoꢀ
induceꢀexcellentꢀlevelsꢀofꢀenantioselectivityꢀinꢀaꢀvarietyꢀofꢀClaisenꢀrear-
rangements:ꢀ(i)ꢀUyeda,ꢀC.;ꢀJacobsen,ꢀE.ꢀN.ꢀEnantioselectiveꢀClaisenꢀRe-
arrangemntsꢀwithꢀaꢀHydrogen-BondꢀDonorꢀCatalyst.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ
2
008,ꢀ 130,ꢀ 9228–9229.ꢀ (j)ꢀ Kaeobamrung,ꢀ J.;ꢀ Mahatthananchai,ꢀ J.;ꢀ
Zheng,ꢀP.;ꢀBode,ꢀJ.ꢀW.ꢀAnꢀEnantioselectiveꢀClaisenꢀRearrangementꢀCata-
lyzedꢀbyꢀN-HeterocyclicꢀCarbenes.ꢀJ.ꢀAm.ꢀChem.ꢀSoc.ꢀ2010,ꢀ132,ꢀ8810–
8
812.ꢀ(k)ꢀRueping,ꢀM.;ꢀAntonchick,ꢀA.ꢀP.ꢀCatalyticꢀAsymmetricꢀAminoal-
8
ACS Paragon Plus Environment