Additions and cycloadditions of 2-phenylallylmagnesium phenoxide to carbon-carbon double bonds

Luteri, George F.; Ford, Warren T.

doi:10.1021/jo00425a010

Cited by 22 publications

(6 citation statements)

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“…These substituents stabilize the developing cyclopentyl anion , cycloadditions of 2-cyano, 2-carbamoyl-, and 2-carbonylallyl anions 6 have been reported. A closely related zwitterionic system, for which calculations indicated some diradical character,7b has been described recently (Scheme B) .…”

Section: Introductionmentioning

confidence: 95%

“…An equally elegant access to pyrrolidine ring systems is provided by the cycloaddition of 2-azaallyl anions and olefins. Numerous examples of both reactions have been reported in the literature. − Frontier orbital considerations (the Woodward−Hoffmann rules) 15 predict that, for these reactions, a concerted 4π s + 2π s cycloaddition mechanism is symmetry-allowed (route A in Scheme ). Alternatively, a two-step pathway may be followed, involving pentenyl or azapentenyl anion intermediates (route B).…”

Section: Introductionmentioning

confidence: 99%

“…A closely related zwitterionic system, for which calculations indicated some diradical character,7b has been described recently (Scheme B) . The scope of this type of reaction has been extended to the synthesis of cyclopentenes via an addition−elimination sequence by introduction of a phenylsulfonyl or phenylthio substituent at a terminal carbon of the allyl anion. 2a,5c,f Since allyl anions are very electron-rich systems, only olefins with aromatic and/or electron-withdrawing substituents were found to be suitable reaction partners for this type of cycloaddition. − The only additions to nonolefinic multiple bonds have been reported for azobenzene 5a,b,d,e and, more recently, for a number of electron-deficient alkynes 7e 1

2 …”

Section: Introductionmentioning

confidence: 99%

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Mechanism of Anionic [3 + 2] Cycloadditions. An ab Initio Computational Study on the Cycloaddition of Allyl-, 2-Borylallyl-, and 2-Azaallyllithium to Ethylene

1998

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The anionic [3 + 2] cycloaddition of allyl anions or allyllithium compounds to double or triple bonds is an elegant route both to carbocyclic and to heterocyclic five-membered rings. The mechanism of such reactions has not yet been established conclusively. In this computational study, the concerted 4πs + 2πs mechanism, expected on the basis of the Woodward−Hoffmann rules, is found to be less favorable than two-step pathways for the cycloadditions of ethylene to the allyl, 2-borylallyl, and 2-azaallyl anions and their lithiated counterparts at Becke3LYP/6-311+G** and MP2(fc)/6-31+G* levels of theory. Except for allyllithium, the 4πs + 2πs cycloadditions (in C s symmetry) are not concerted, since only second-order saddle points, rather than true transition structures, are involved. The anisotropy of the reactant polarizabilities is responsible. Instead, two-step cycloaddition pathways are followed by all three model systems. In accord with experimental experience, 2-borylallyl and 2-azaallyl compounds are found to undergo this type of reaction more readily than the unsubstituted allyl anion or allyllithium. The second, ring-closing step is facilitated by the anion-stabilizing effect of nitrogen and the boryl substituent.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

2 …”

Section: Introductionmentioning

confidence: 99%

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Mechanism of Anionic [3 + 2] Cycloadditions. An ab Initio Computational Study on the Cycloaddition of Allyl-, 2-Borylallyl-, and 2-Azaallyllithium to Ethylene

1998

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“…Le retour aux especes de type A se produit par addition 1,3 du monomere sur les carbanions phenyl allyliques B et C. Une reaction analogue, en presence d'agents complexants, a ete precedemment signalee pour differents systemes (10)(11)(12). La nouvelle espece cylique formee presente ur,e structure electronique tres proche de celle de l'espece A et doit donc absorber sensiblement a la m2me longueur d'onde.…”

Section: Stabilite'des Centres Actifs Lithieunclassified

La polymérisation anionique en masse de l'α-méthyl styrène. I. Etude de la stabilité des centres actifs

Adès¹,

Fontanille²,

Léonard³

1982

Can. J. Chem.

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R e~u le 1 avril 198 1 DOMINIQUE ADES, MICHEL FONTANILLE et JACQUES LEONARD. Can. J . Chem. 60,564 (1982). Lapolymerisation anionique en masse de I'a-methyl styrene (EMS) a ete realisee en utilisant comme amorceur le tert-butyllithium (t-BuLi) avec ou sans N,N,N1,N'-tetramethyl ethylene diamine (TMEDA). En absence de TMEDA, les centres actifs formes se degradent rapidement a 62°C tandis qu'ils sont relativement plus stables a 25°C. En presence de TMEDA, la stabilite des centres actifs est beaucoup plus grande mais elle est fonction de I'ordre dans lequel le t-BuLi et la TMEDA sont ajoutes a I'ctMS. La stabilite des centres actifs est aussi fonction du rapport r = The anionic bulk polymerization of cc-methylstyrene (EMS) has been carried out using tert-butyllithium (t-BuLi) as initiator with or without N,N,N1,N'-tetramethylethylenediamine (TMEDA). In absence of TMEDA, the "livingends" are rapidly deactivated at 62°C whereas they are relatively more stable at 25°C. The "living ends" are much more stable in presence of TMEDA; however, their stability is a function of the order in which t-BuLi and TMEDA are added to EMS. The stability of "living ends" is also a function of the ratio r = [TMEDA]l[t-BuLi] and best results are obtained with a one to one ratio. At high temperature, the formation of species with absorption bands at 390 and 424 nm and the broadening of the molecular weight distribution are observed. These results are explained in terms of a transfer reaction to the monomer or to the deactivated polymer.

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“…3 2-Phenylallylmagnesium phenoxide in THF/HMPA also cycloadds to a variety of other electrondeficient olefins. 4 Treatment of 1,3-diphenylpropyne with lithium diisopropylamide (LDIA) in hexane gives a cyclic dimer.5 2-Cyano-1,3-diphenylallyllithium cycloadds to styrene, Zrzzzzs-stilbene, 1,1 -diphenylethylene, and acenaphthylene. 6 Reaction of a 2-thiomethylenecyclohexanone derivative with LDIA forms a thioallyl anion which adds to ethyl acrylate and to diethyl fumarate to form hydrindanones.…”

mentioning

confidence: 99%

Stereochemistry of addition of 2-cyano-1,3-diphenylallyllithium to trans-stilbene, an anionic [3 + 2] cycloaddition

Ford¹,

Luteri²

1977

J. Am. Chem. Soc.

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Additions and cycloadditions of 2-phenylallylmagnesium phenoxide to carbon-carbon double bonds

Cited by 22 publications

References 22 publications

Mechanism of Anionic [3 + 2] Cycloadditions. An ab Initio Computational Study on the Cycloaddition of Allyl-, 2-Borylallyl-, and 2-Azaallyllithium to Ethylene

Mechanism of Anionic [3 + 2] Cycloadditions. An ab Initio Computational Study on the Cycloaddition of Allyl-, 2-Borylallyl-, and 2-Azaallyllithium to Ethylene

La polymérisation anionique en masse de l'α-méthyl styrène. I. Etude de la stabilité des centres actifs

Stereochemistry of addition of 2-cyano-1,3-diphenylallyllithium to trans-stilbene, an anionic [3 + 2] cycloaddition

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