corey house

8/17/2019 Corey House

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Corey-Fuchs Reaction

This two step methodology allows the preparation of terminalalkynes by one-carbon homologation of an aldehyde. The rststep is comparable to a Wittig Reaction , and leads to adibromoalkene. Treatment with a lithium base (Bu i, !"#generates a bromoalkyne intermediate $ia dehydrohalogenation,which undergoes metal-halogen e%change under the reactionconditions and yields the terminal alkyne upon work-up.

" modi cation of the &orey-'uchs Reaction in$ol$es the reactionof the intermediate alkynyllithium with an electrophile prior toa ueous work-up, gi$ing a chain e%tension product)

Mechanism of the Corey-Fuchs Reaction

*n the formation of the ylide from &Br +, two e ui$alents of triphenylphosphine are used. ne e ui$alent forms the ylide whilethe other acts as reducing agent and bromine sca$enger.

The addition of the ylide to the aldehyde)

http://www.organic-chemistry.org/namedreactions/wittig-reaction.shtmhttp://www.organic-chemistry.org/namedreactions/wittig-reaction.shtm


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Reaction of the dibromoalkene with Bu i)

Corey House reaction with mechanism

The Corey–House synthesis (also called the Corey–Posner,Whitesides–House reaction and other permutations# isan organic reaction that in$ol$es the reaction of a lithium dialkyl cuprate with an alkyl halide to form a new alkane ,an organocopper compound and a lithium halide .

R &u i R/-0 1 R-R/ R&u i0

Reaction mechanism

This reaction occurs in two steps. The alkyl halide is treated withlithium metal, and sol$ated in dry ether, which con$erts the alkylhalide into an alkyl lithium compound, R- i. The starting R-0 canbe primary, secondary or tertiary alkyl halide :

R-X + 2Li → R-Li + Li-X

https://en.wikipedia.org/wiki/Organic_reactionhttps://en.wikipedia.org/wiki/Lithiumhttps://en.wikipedia.org/wiki/Cupratehttps://en.wikipedia.org/wiki/Alkyl_halidehttps://en.wikipedia.org/wiki/Alkanehttps://en.wikipedia.org/wiki/Halidehttps://en.wikipedia.org/wiki/Organic_reactionhttps://en.wikipedia.org/wiki/Lithiumhttps://en.wikipedia.org/wiki/Cupratehttps://en.wikipedia.org/wiki/Alkyl_halidehttps://en.wikipedia.org/wiki/Alkanehttps://en.wikipedia.org/wiki/Halide


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The second step re uires the alkyl lithium compound to betreated with cuprous iodide (&u*#. This creates a lithium dialkylcuprate compound. These compounds were rst synthesi2edby 3enry 4ilman of *owa 5tate 6ni$ersity , and are usually

called 4ilman reagents in honor of his contributions)R i &u* 1 R &u i i*

The lithium dialkyl cuprate is then treated with the second alkylhalide, which couples to the compound)

R &u i R/-0 1 R-R/ R&u i0

*f second alkyl halide is not the same as the rst, then cross-products are formed.

*t is important to note that for this reaction to work successfully,the second alkyl halide must be a methyl halide, ben2yl halide,primary alkyl halide or a secondary cyclo alkyl halide. Therelati$e simplicity of this reaction makes it a useful techni ue forsynthesi2ing organic compounds.

Johnson–Corey–Chaykovsky reaction

The Johnson–Corey–Chaykovsky reaction

(sometimes referred to as the Corey–Chaykovskyreaction or CCR #

is a chemical reaction used in organic chemistry for the synthesisof epo%ides , a2iridines , and cyclopropanes . *t was disco$ered in7897 by ". William :ohnson and de$eloped signi cantly by ;. :.&orey and


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The reaction is most often employed for epo%idation$ia methylene transfer, and to this end has been used in se$eralnotable total syntheses (5ee 5ynthesis of epo%ides below#."dditionally detailed below are the history, mechanism, scope,and enantioselecti$e $ariants of the reaction. 5e$eral re$iewsha$e been published.

History

The original publication by :ohnson concerned the reaction of 8-dimethylsulfonium >uorenylide withsubstituted ben2aldehyde deri$ati$es. The attempted Wittig-likereaction failed and a ben2al>uorene o%ide was obtained instead,

noting that ?Reaction between the sulfur ylid and ben2aldehydesdid not a@ord ben2al>uorenes as had the phosphorus and arsenicylids.

The subse uent de$elopment of (dimethylo%osulfaniumyl#methanide, (&3 =# 5 &3 and(dimethylsulfaniumyl#methanide, (&3 =# 5&3 (known as Corey–Chaykovsky reagents # by &orey and &hayko$sky as eAcient

https://en.wikipedia.org/wiki/Methylene_(compound)https://en.wikipedia.org/wiki/Total_syntheseshttps://en.wikipedia.org/wiki/Johnson%E2%80%93Corey%E2%80%93Chaykovsky_reaction#Synthesis_of_epoxideshttps://en.wikipedia.org/wiki/Benzaldehydehttps://en.wikipedia.org/wiki/Wittig_reactionhttps://en.wikipedia.org/wiki/Wittig_reactionhttps://en.wikipedia.org/wiki/Methylene_(compound)https://en.wikipedia.org/wiki/Total_syntheseshttps://en.wikipedia.org/wiki/Johnson%E2%80%93Corey%E2%80%93Chaykovsky_reaction#Synthesis_of_epoxideshttps://en.wikipedia.org/wiki/Benzaldehydehttps://en.wikipedia.org/wiki/Wittig_reactionhttps://en.wikipedia.org/wiki/Wittig_reaction


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methylene-transfer reagents established the reaction as a part of the organic canon.

Mechanism

The reaction mechanism for the :ohnson &orey &hayko$skyreaction consists of nucleophilic addition of the ylide tothe carbonyl or imine group. " negati$e charge is transferred tothe heteroatom and because the sulfonium cation is a

good lea$ing group it gets e%pelled forming the ring. *n therelated Wittig reaction , the formation of the muchstronger phosphorus -o%ygen doublebond pre$ents o%irane formation and instead, ole nation takesplace through a +-membered cyclic intermediate.

The trans diastereoselecti$ity obser$ed results from there$ersibility of the initial addition, allowing e uilibration to thefa$ored anti betaine o$er the syn betaine. *nitial addition of theylide results in a betaine with adCacent chargesD density functionaltheory calculations ha$e shown that the rate-limiting step is

rotation of the central bond into the conformer necessaryfor backside attack on the sulfonium.

https://en.wikipedia.org/wiki/Reaction_mechanismhttps://en.wikipedia.org/wiki/Nucleophilic_additionhttps://en.wikipedia.org/wiki/Ylidehttps://en.wikipedia.org/wiki/Carbonylhttps://en.wikipedia.org/wiki/Iminehttps://en.wikipedia.org/wiki/Heteroatomhttps://en.wikipedia.org/wiki/Sulfoniumhttps://en.wikipedia.org/wiki/Cationhttps://en.wikipedia.org/wiki/Leaving_grouphttps://en.wikipedia.org/wiki/Wittig_reactionhttps://en.wikipedia.org/wiki/Phosphorushttps://en.wikipedia.org/wiki/Oxygenhttps://en.wikipedia.org/wiki/Double_bondhttps://en.wikipedia.org/wiki/Double_bondhttps://en.wikipedia.org/wiki/Oxiranehttps://en.wikipedia.org/w/index.php?title=Olefination&action=edit&redlink=1https://en.wikipedia.org/wiki/Diastereoselectivityhttps://en.wikipedia.org/wiki/Betainehttps://en.wikipedia.org/wiki/Density_functional_theoryhttps://en.wikipedia.org/wiki/Density_functional_theoryhttps://en.wikipedia.org/wiki/Rate-limiting_stephttps://en.wikipedia.org/wiki/Nucleophilic_additionhttps://en.wikipedia.org/wiki/Reaction_mechanismhttps://en.wikipedia.org/wiki/Nucleophilic_additionhttps://en.wikipedia.org/wiki/Ylidehttps://en.wikipedia.org/wiki/Carbonylhttps://en.wikipedia.org/wiki/Iminehttps://en.wikipedia.org/wiki/Heteroatomhttps://en.wikipedia.org/wiki/Sulfoniumhttps://en.wikipedia.org/wiki/Cationhttps://en.wikipedia.org/wiki/Leaving_grouphttps://en.wikipedia.org/wiki/Wittig_reactionhttps://en.wikipedia.org/wiki/Phosphorushttps://en.wikipedia.org/wiki/Oxygenhttps://en.wikipedia.org/wiki/Double_bondhttps://en.wikipedia.org/wiki/Double_bondhttps://en.wikipedia.org/wiki/Oxiranehttps://en.wikipedia.org/w/index.php?title=Olefination&action=edit&redlink=1https://en.wikipedia.org/wiki/Diastereoselectivityhttps://en.wikipedia.org/wiki/Betainehttps://en.wikipedia.org/wiki/Density_functional_theoryhttps://en.wikipedia.org/wiki/Density_functional_theoryhttps://en.wikipedia.org/wiki/Rate-limiting_stephttps://en.wikipedia.org/wiki/Nucleophilic_addition


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The degree of re$ersibility in the initial step (and therefore thediastereoselecti$ity# depends on four factors, with greaterre$ersibility corresponding to higher selecti$ity)

7. Stability of the substrate with higher stability leading togreater re$ersibility by fa$oring the starting material o$erthe betaine.

. Stability of the ylide with higher stability similarly leading togreater re$ersibility.

=. Steric hindrance in the betaine with greater hindranceleading to greater re$ersibility by disfa$oring formation ofthe intermediate and slowing the rate-limiting rotation of thecentral bond.

+. Solvation of charges in the betaine by counterions suchas lithium with greater sol$ation allowing more facilerotation in the betaine intermediate, lowering the amount ofre$ersibility.

https://en.wikipedia.org/wiki/Steric_hindrancehttps://en.wikipedia.org/wiki/Counterionhttps://en.wikipedia.org/wiki/Lithiumhttps://en.wikipedia.org/wiki/Steric_hindrancehttps://en.wikipedia.org/wiki/Counterionhttps://en.wikipedia.org/wiki/Lithium


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Scope

The application of the :ohnson &orey &hayko$sky reaction in

organic synthesis is di$erse. The reaction has come to encompassreactions of many types of sulfur ylides with electrophiles wellbeyond the original publications. *t has seen use in a number of high-pro le total syntheses, as detailed below, and is generallyrecogni2ed as a powerful transformati$e tool in the organicrepertoire.

Types o y!ides

uence the ease of preparation for thereagents (typically from the sulfonium halide,e.g. trimethylsulfonium iodide # and o$erall reaction rate in $ariousways. The general format for the reagent is shown on the right.

6se of a sulfo%onium allows more facile preparation of the reagentusing weaker bases as compared to sulfonium ylides. (Thedi@erence being that a sulfo%onium contains a doubly bonded

o%ygen whereas the sulfonium does not.# The former react slowerdue to their increased stability. *n addition, the dialkylsulfo%ide by-products of sulfo%onium reagents are greatly preferred to thesigni cantly more to%ic, $olatile, and odorous dialkylsul de by-products from sulfonium reagents. E7F

The $ast maCority of reagents are monosubstituted at the ylidecarbon (either R 7 or R as hydrogen#. !isubstituted reagents aremuch rarer but ha$e been described)

7. *f the ylide carbon is substituted with an electron-withdrawing group (;W4#, the reagent is referred to asa stabilized ylide . These, similarly to sulfo%onium reagents,react much slower and are typically easier to prepare. Theseare limited in their usefulness as the reaction can becomeprohibiti$ely sluggish) e%amples in$ol$ing amides arewidespread, with many fewer in$ol$ing esters and $irtually

https://en.wikipedia.org/wiki/Electrophilehttps://en.wikipedia.org/wiki/Trimethylsulfonium_iodidehttps://en.wikipedia.org/wiki/Dimethyl_sulfoxidehttps://en.wikipedia.org/wiki/By-producthttps://en.wikipedia.org/wiki/By-producthttps://en.wikipedia.org/wiki/Dimethylsulfidehttps://en.wikipedia.org/wiki/Johnson%E2%80%93Corey%E2%80%93Chaykovsky_reaction#cite_note-Aggrawal2003-1https://en.wikipedia.org/wiki/Electron-withdrawing_grouphttps://en.wikipedia.org/wiki/Electron-withdrawing_grouphttps://en.wikipedia.org/wiki/Amidehttps://en.wikipedia.org/wiki/Esterhttps://en.wikipedia.org/wiki/Electrophilehttps://en.wikipedia.org/wiki/Trimethylsulfonium_iodidehttps://en.wikipedia.org/wiki/Dimethyl_sulfoxidehttps://en.wikipedia.org/wiki/By-producthttps://en.wikipedia.org/wiki/By-producthttps://en.wikipedia.org/wiki/Dimethylsulfidehttps://en.wikipedia.org/wiki/Johnson%E2%80%93Corey%E2%80%93Chaykovsky_reaction#cite_note-Aggrawal2003-1https://en.wikipedia.org/wiki/Electron-withdrawing_grouphttps://en.wikipedia.org/wiki/Electron-withdrawing_grouphttps://en.wikipedia.org/wiki/Amidehttps://en.wikipedia.org/wiki/Ester


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no e%amples in$ol$ing other ;W4/s. 'or these, therelated !ar2ens reaction is typically more appropriate.

. *f the ylide carbon is substituted with an aryl or allyl group,the reagent is referred to as a semi-stabilized ylide . Theseha$e been de$eloped e%tensi$ely, second only to theclassical methylene reagents (R 7GR G3#. The substitutionpattern on aryl reagents can hea$ily in>uence the selecti$ityof the reaction as per the criteria abo$e.

=. *f the ylide carbon is substituted with an alkyl group thereagent is referred to as an unstabilized ylide . The si2e of the alkyl groups are the maCor factors in selecti$ity withthese reagents.

The R-groups on the sulfur, though typically methyls , ha$e beenused to synthesi2e reagents that canperform enantioselecti$e $ariants of the reaction (5ee Hariationsbelow#. The si2e of the groups can alsoin>uence diastereoselecti$ity in alicyclic substrates .

Synthesis of epoxidesReactions of sulfur ylides with ketones and aldehydes toform epo%ides are by far the most common application of the

:ohnson &orey &hayko$sky reaction. ;%amples in$ol$ing comple%substrates and /e%otic/ ylides ha$e been reported, as shownbelow.

The reaction has been used in a number of notable totalsyntheses including the !anishefsky Ta%ol total synthesis , whichproduces the chemotherapeutic drug ta%ol , and the Iuehne5trychnine total synthesis which produces thepesticide strychnine .

https://en.wikipedia.org/wiki/Darzens_reactionhttps://en.wikipedia.org/wiki/Arylhttps://en.wikipedia.org/wiki/Allylhttps://en.wikipedia.org/wiki/Methylene_grouphttps://en.wikipedia.org/wiki/Methylhttps://en.wikipedia.org/wiki/Enantioselectivehttps://en.wikipedia.org/wiki/Diastereoselectivityhttps://en.wikipedia.org/wiki/Alicyclichttps://en.wikipedia.org/wiki/Ketonehttps://en.wikipedia.org/wiki/Aldehydehttps://en.wikipedia.org/wiki/Epoxidehttps://en.wikipedia.org/wiki/Danishefsky_Taxol_total_synthesishttps://en.wikipedia.org/wiki/Chemotherapyhttps://en.wikipedia.org/wiki/Taxolhttps://en.wikipedia.org/wiki/Strychnine_total_synthesis#Kuehne_synthesishttps://en.wikipedia.org/wiki/Strychnine_total_synthesis#Kuehne_synthesishttps://en.wikipedia.org/wiki/Strychninehttps://en.wikipedia.org/wiki/Darzens_reactionhttps://en.wikipedia.org/wiki/Arylhttps://en.wikipedia.org/wiki/Allylhttps://en.wikipedia.org/wiki/Methylene_grouphttps://en.wikipedia.org/wiki/Methylhttps://en.wikipedia.org/wiki/Enantioselectivehttps://en.wikipedia.org/wiki/Diastereoselectivityhttps://en.wikipedia.org/wiki/Alicyclichttps://en.wikipedia.org/wiki/Ketonehttps://en.wikipedia.org/wiki/Aldehydehttps://en.wikipedia.org/wiki/Epoxidehttps://en.wikipedia.org/wiki/Danishefsky_Taxol_total_synthesishttps://en.wikipedia.org/wiki/Chemotherapyhttps://en.wikipedia.org/wiki/Taxolhttps://en.wikipedia.org/wiki/Strychnine_total_synthesis#Kuehne_synthesishttps://en.wikipedia.org/wiki/Strychnine_total_synthesis#Kuehne_synthesishttps://en.wikipedia.org/wiki/Strychnine


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Synthesis of aziridines The synthesis of a2iridines from imines is another importantapplication of the :ohnson &orey &hayko$sky reaction andpro$ides an alternati$e to amine transfer from o%a2iridines .

Though less widely applied, the reaction has a similar substratescope and functional group tolerance to the carbonyl e ui$alent.

The e%amples shown below are representati$eD in the latter, ana2iridine forms in situ and is opened $ia nucleophilic attack toform the corresponding amine .

Synthesis of cyclopropanes'or addition of sulfur ylides to enones, higher 7,+-selecti$ity istypically obtained with sulfo%onium reagents than with sulfoniumreagents.


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and amides (the e%ample below in$ol$es a Weinreb amide #. Withfurther conCugated systems 7,9-addition tends to predominateo$er 7,+-addition.

Other reactions

*n addition to the reactions originally reported by :ohnson, &orey,and &hayko$sky, sulfur ylides ha$e been used for a number of related homologation reactions that tend to be grouped under thesame name.

• With epo%ides and a2iridines the reaction ser$es as a ring-e%pansion to produce the corresponding o%etane or a2etidine .

The long reaction times re uired for these reactions pre$ent

them from occurring as signi cant side reactions whensynthesi2ing epo%ides and a2iridines.

https://en.wikipedia.org/wiki/Amidehttps://en.wikipedia.org/wiki/Weinreb_amidehttps://en.wikipedia.org/wiki/Homologation_reactionhttps://en.wikipedia.org/wiki/Epoxidehttps://en.wikipedia.org/wiki/Aziridinehttps://en.wikipedia.org/wiki/Oxetanehttps://en.wikipedia.org/wiki/Azetidinehttps://en.wikipedia.org/wiki/Side_reactionhttps://en.wikipedia.org/wiki/Amidehttps://en.wikipedia.org/wiki/Weinreb_amidehttps://en.wikipedia.org/wiki/Homologation_reactionhttps://en.wikipedia.org/wiki/Epoxidehttps://en.wikipedia.org/wiki/Aziridinehttps://en.wikipedia.org/wiki/Oxetanehttps://en.wikipedia.org/wiki/Azetidinehttps://en.wikipedia.org/wiki/Side_reaction


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• 5e$eral cycloadditions wherein the ylide ser$es as a?nucleophilic carbenoid e ui$alent? ha$e been reported.

• i$ing polymeri2ations using trialkylboranes as the catalystand (dimethylo%osulfaniumyl#methanide as the monomer ha$ebeen reported for the synthesis of $arious comple% polymers.

"nantiose!ective variations

The de$elopment of an enantioselecti$e (i.e. yieldingan enantiomeric e%cess , which is labelled as ?ee?# $ariant of the

:ohnson &orey &hayko$sky reaction remains an acti$e area of academic research. The use of chiral sul des ina stoichiometric fashion has pro$ed more successful than the

corresponding catalytic $ariants, but the substrate scope is stilllimited in all cases. The catalytic $ariants ha$e been de$elopedalmost e%clusi$ely for enantioselecti$e purposesD typicalorganosul de reagents are not prohibiti$ely e%pensi$e and theracemic reactions can be carried out with e uimolar amounts of ylide without raising costs signi cantly. &hiral sul des, on the

https://en.wikipedia.org/wiki/Cycloadditionhttps://en.wikipedia.org/wiki/Nucleophilichttps://en.wikipedia.org/wiki/Carbenehttps://en.wikipedia.org/wiki/Living_polymerizationhttps://en.wikipedia.org/wiki/Organoboranehttps://en.wikipedia.org/wiki/Enantioselectivehttps://en.wikipedia.org/wiki/Enantiomeric_excesshttps://en.wikipedia.org/wiki/Chirality_(chemistry)https://en.wikipedia.org/wiki/Stoichiometrichttps://en.wikipedia.org/wiki/Catalytichttps://en.wikipedia.org/wiki/Cycloadditionhttps://en.wikipedia.org/wiki/Nucleophilichttps://en.wikipedia.org/wiki/Carbenehttps://en.wikipedia.org/wiki/Living_polymerizationhttps://en.wikipedia.org/wiki/Organoboranehttps://en.wikipedia.org/wiki/Enantioselectivehttps://en.wikipedia.org/wiki/Enantiomeric_excesshttps://en.wikipedia.org/wiki/Chirality_(chemistry)https://en.wikipedia.org/wiki/Stoichiometrichttps://en.wikipedia.org/wiki/Catalytic


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other hand, are more costly to prepare, spurring the ad$ancementof catalytic enantioselecti$e methods.

Stoichiometric reagents

The most successful reagents employed in a stoichiometricfashion are shown below. The rst is a bicyclic o%athiane that hasbeen employed in the synthesis of the J-adrenergiccompound dichloroisoproterenol (!&*# but is limited by thea$ailability of only one enantiomer of the reagent. The synthesisof the a%ial diastereomer is rationali2ed $ia the 7,=- anomerice@ect which reduces the nucleophilicity of the e uatorial lonepair . The conformation of the ylide is limited by transannularstrain and approach of the aldehyde is limited to one face of theylide by steric interactions with the methyl substituents. E F

The other maCor reagent is a camphor -deri$ed reagent de$eloped

by Harinder "ggarwal of the 6ni$ersity of Bristol .Both enantiomers are easily synthesi2ed, although the yields arelower than for the o%athiane reagent. The ylide conformation isdetermined by interaction with the bridgehead hydrogens andapproach of the aldehyde is blocked by the camphor moiety . Thereaction employs a phospha2ene base to promote formation of the ylide.

https://en.wikipedia.org/wiki/Bicyclichttps://en.wikipedia.org/wiki/Axial_bondhttps://en.wikipedia.org/wiki/Anomeric_effecthttps://en.wikipedia.org/wiki/Anomeric_effecthttps://en.wikipedia.org/wiki/Equatorial_bondhttps://en.wikipedia.org/wiki/Lone_pairhttps://en.wikipedia.org/wiki/Lone_pairhttps://en.wikipedia.org/wiki/Conformational_isomerismhttps://en.wikipedia.org/wiki/Transannular_strainhttps://en.wikipedia.org/wiki/Transannular_strainhttps://en.wikipedia.org/wiki/Johnson%E2%80%93Corey%E2%80%93Chaykovsky_reaction#cite_note-Aggrawal2004-2https://en.wikipedia.org/wiki/Camphorhttps://en.wikipedia.org/wiki/University_of_Bristolhttps://en.wikipedia.org/wiki/Enantiomerhttps://en.wikipedia.org/wiki/Bicyclic_moleculehttps://en.wikipedia.org/wiki/Moiety_(chemistry)https://en.wikipedia.org/wiki/Phosphazenehttps://en.wikipedia.org/wiki/Bicyclichttps://en.wikipedia.org/wiki/Axial_bondhttps://en.wikipedia.org/wiki/Anomeric_effecthttps://en.wikipedia.org/wiki/Anomeric_effecthttps://en.wikipedia.org/wiki/Equatorial_bondhttps://en.wikipedia.org/wiki/Lone_pairhttps://en.wikipedia.org/wiki/Lone_pairhttps://en.wikipedia.org/wiki/Conformational_isomerismhttps://en.wikipedia.org/wiki/Transannular_strainhttps://en.wikipedia.org/wiki/Transannular_strainhttps://en.wikipedia.org/wiki/Johnson%E2%80%93Corey%E2%80%93Chaykovsky_reaction#cite_note-Aggrawal2004-2https://en.wikipedia.org/wiki/Camphorhttps://en.wikipedia.org/wiki/University_of_Bristolhttps://en.wikipedia.org/wiki/Enantiomerhttps://en.wikipedia.org/wiki/Bicyclic_moleculehttps://en.wikipedia.org/wiki/Moiety_(chemistry)https://en.wikipedia.org/wiki/Phosphazene


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Catalytic reagents

&atalytic reagents ha$e been less successful, with most $ariationssu@ering from poor yield, poor enantioselecti$ity, or both. Thereare also issues with substrate scope, most ha$ing limitations withmethylene transfer and aliphatic aldehydes . The trouble stemsfrom the need for a nucleophilic sul de that eAciently generatesthe ylide which can also act as a good lea$ing group to form theepo%ide. 5ince the factors underlying these desiderata are atodds, tuning of the catalyst properties has pro$en diAcult. 5hownbelow are se$eral of the most successful catalysts along with theyields and enantiomeric e%cess for their use in synthesis of (;#-stilbene o%ide.

"ggarwal has de$eloped an alternati$e method employing thesame sul de as abo$e and a no$el alkylation in$ol$inga rhodium carbenoid formed in situ . The method too has limitedsubstrate scope, failing for any electrophiles possessing basicsubstituents due to competiti$e consumption of the carbenoid.

https://en.wikipedia.org/wiki/Aliphatichttps://en.wikipedia.org/wiki/Aldehydehttps://en.wikipedia.org/wiki/Nucleophilichttps://en.wikipedia.org/wiki/Leaving_grouphttps://en.wikipedia.org/wiki/(E)-stilbenehttps://en.wikipedia.org/wiki/(E)-stilbenehttps://en.wikipedia.org/wiki/Rhodiumhttps://en.wikipedia.org/wiki/Transition_metal_carbene_complexhttps://en.wikipedia.org/wiki/In_situhttps://en.wikipedia.org/wiki/Electrophilehttps://en.wikipedia.org/wiki/Reaction_ratehttps://en.wikipedia.org/wiki/Aliphatichttps://en.wikipedia.org/wiki/Aldehydehttps://en.wikipedia.org/wiki/Nucleophilichttps://en.wikipedia.org/wiki/Leaving_grouphttps://en.wikipedia.org/wiki/(E)-stilbenehttps://en.wikipedia.org/wiki/(E)-stilbenehttps://en.wikipedia.org/wiki/Rhodiumhttps://en.wikipedia.org/wiki/Transition_metal_carbene_complexhttps://en.wikipedia.org/wiki/In_situhttps://en.wikipedia.org/wiki/Electrophilehttps://en.wikipedia.org/wiki/Reaction_rate


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corey house

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