Synthesis of 1,3-dienes bearing both electron-donor and acceptor substituents

Moreau, Pascale; Neirabeyeh, M. Al; Guillaumet, Gérald; Coudert, G.

doi:10.1016/0040-4039(91)80074-g

Cited by 29 publications

(8 citation statements)

References 8 publications

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“…1 and 2) consist of a quinoxaline ring system with two p-tosyl and one substituted benzylidene group at the 1-, 4-and 2-positions, respectively. The E con®guration of the molecules of (II) and (III), as established from the 3 J CÐH coupling constant (Moreau et al, 1991;Cabiddu et al, 1986) value of 7.76 Hz for both compounds, is con®rmed by the N1ÐC22ÐC23ÐC24 torsion angle of À172.0 (1) for (II) and 171.7 (2) for (III). The pyrazine ring (B; N1/C8/C13/N2/C21/C22) fused to the benzene ring (A; C8± C13) in both compounds assumes a half-chair conformation, with ring-puckering parameters (Cremer & Pople, 1975) Q, and 9 of 0.413 (1) A Ê , 49.7 (2) and 264.5 (2) , respectively, for (II), and 0.413 (2) A Ê , 132.0 (3) and 77.8 (3) , respectively, for (III).…”

Section: Commentmentioning

confidence: 92%

Two (E)-2-arylidene-1,4-di-p-tosyl-1,2,3,4-tetrahydroquinoxaline compounds: supramolecular frameworks built with C—H...O and C—H...π(arene) hydrogen bonds and π–π stacking interactions

2007

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The pyrazine ring in two N-substituted quinoxaline derivatives, namely (E)-2-(2-methoxybenzylidene)-1,4-di-p-tosyl-1,2,3,4-tetrahydroquinoxaline, C(30)H(28)N(2)S(2)O(5), (II), and (E)-methyl 2-[(1,4-di-p-tosyl-1,2,3,4-tetrahydroquinoxalin-2-ylidene)methyl]benzoate, C(31)H(28)N(2)S(2)O(6), (III), assumes a half-chair conformation and is shielded by the terminal tosyl groups. In the molecular packing of the compounds, intermolecular C-H...O hydrogen bonds between centrosymmetrically related molecules generate dimeric rings, viz. R(2)(2)(22) in (II) and R(2)(2)(26) in (III), which are further connected through C-H...pi(arene) hydrogen bonds and pi-pi stacking interactions into novel supramolecular frameworks.

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Section: Commentmentioning

confidence: 92%

Two (E)-2-arylidene-1,4-di-p-tosyl-1,2,3,4-tetrahydroquinoxaline compounds: supramolecular frameworks built with C—H...O and C—H...π(arene) hydrogen bonds and π–π stacking interactions

2007

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“…9 Here we studied reactions of 2 (hydroxymethyl)benzo furans 9a-e, 3 (hydroxymethyl)indole (10), and 1 hydroxy 6 methyl 1,2,3,4 tetrahydrocarbazole (11) with acetal 3.…”

Section: Methodsmentioning

confidence: 99%

A study of the Claisen—Eschenmoser reaction for hydroxymethylbenzofurans and-indoles

et al. 2007

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“…Quite good yields were obtaind starting fom the primary or secondary alcohol, when very low yields were obtained using tertiary alcohols or secondary benzylic alcohols. When these allylic benzodioxinic alcohols 17 were heated in refluxing xylene with N,N-dimethylacetamide dimethylacetal (Eschenmoser procedure), the 3-substituted-2-alkylidene-2,3-dihydro-1,4-benzodioxins 19 were obtained in quite better yields and shorter reaction time, whatever the alcohol used [35].…”

Section: Non-organometallic-catalyzed Syn-thesismentioning

confidence: 98%

“…Reaction of 2-lithiobenzodioxin with aldehydes or ketones gave the corresponding allylic benzodioxinic alcohols 17 (Scheme 6) [35]. Submission of these compounds to the orthoester Claisen rearrangement afforded the 3-substituted-2-alkylidene-2,3-dihydro-1,4-benzodioxins 18.…”

Section: Non-organometallic-catalyzed Syn-thesismentioning

confidence: 98%

Synthesis of 2,3-Dihydro-2-Ylidene-1,4-Benzodioxins

Sinou¹

2005

COC

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The 2,3-dihydro-1,4-benzodioxin structure is present in compounds having some interesting biological properties. The first access to this structure, performed from 2-alkyl-1,4-benzodioxin or benzene-1,2-diol via stoechiometric cyclization, generally gave mixtures of products. Recently, the organometallic-catalyzed synthesis of this structure was performed using mercuric oxide, or more interesting, palladium as the catalyst. The palladiumcatalyzed heteroannulation of various monoprop-2-ynylated catechol and aryl iodides in the presence of PdCl 2(PPh3)2 and CuI afforded the corresponding 1-alkylidene or 1-arylidene-2,3-dihydro-1,4-benzodioxins in excellent chemical yields. However the palladium-catalyzed cyclisation of substituted benzene-1,2-diols with different propargylic carbonates gave the corresponding 1-alkylidene or 1-arylidene-2,3-dihydro-1,4-benzodioxins eventually substituted at position 2 by an aryl or an alkyl group. Moreover, this later methodology seems very powerful since it is possible to perform this heteroannulation in an asymmetric way in order to obtain the 1-alkyl-2-alkylidene-2,3-dihydro-1,4-benzodioxins in enantioselectivities up to 96%.

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Synthesis of 1,3-dienes bearing both electron-donor and acceptor substituents

Cited by 29 publications

References 8 publications

Two (E)-2-arylidene-1,4-di-p-tosyl-1,2,3,4-tetrahydroquinoxaline compounds: supramolecular frameworks built with C—H...O and C—H...π(arene) hydrogen bonds and π–π stacking interactions

Two (E)-2-arylidene-1,4-di-p-tosyl-1,2,3,4-tetrahydroquinoxaline compounds: supramolecular frameworks built with C—H...O and C—H...π(arene) hydrogen bonds and π–π stacking interactions

A study of the Claisen—Eschenmoser reaction for hydroxymethylbenzofurans and-indoles

Synthesis of 2,3-Dihydro-2-Ylidene-1,4-Benzodioxins

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