Reactivity of benzyne toward anthracene systems

Klanderman, B. H.; Criswell, Thomas R.

doi:10.1021/jo01263a046

Cited by 48 publications

(26 citation statements)

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“…The presence of sterically demanding groups can hinder the cycloaddition process but can also lead to increased reaction rates, an effect that has been attributed to the release of compression placed on bulky groups by the peri hydrogens of anthracene with the change in hybridization from sp 2 to sp 3 that occurs in the Diels−Alder reaction. 15,16 Many researchers have noticed the production of a transient color that disappears as the Diels−Alder reaction proceeds. This has been attributed to the formation of a charge-transfer complex (CTC) and has been taken as providing evidence for a concerted mechanism.…”

Section: ■ Discussionmentioning

confidence: 99%

“…The other products arise from addition across C 1 and C 4 of the anthracene so as to form 9,10-diferrocenyl-2,3-(c-1-methylpyrrol-2,5-diono)-1,2,3,4-tetrahydro-1,4-ethenoanthracene in both the endo (14) and exo (15) forms. A bird's-eye view of the structure of 14 is shown as Figure 6a and clearly shows the endo orientation of the maleimide adduct.…”

Section: Organometallicsmentioning

confidence: 99%

“…Data for 6 (signals of meso conformer) are as follows. 1 H NMR (500 MHz, CDCl 3 ): δ 8.82 (2H, d, J = 8 Hz,H 8,13 ),7.43 (2H,d,J = 8 Hz,H 5,16 ),7.17 (2H,t,J = 8 Hz,H 7,14 ),7.09 (2H,m,H 6,15 ),5.72 (1H,s,(H 10 ),4.72 (2H,m,H 18,21 ),4.61 (2H,m,H 19,20 ),4.30 (5H,s, ). 13 C NMR (125 MHz,CDCl 3 ): δ 145.4 (C 8b,11 ), 145.3 (C 8a,12 ), 125.6 (C 6,15 ), 125.2 (C 8,13 ), 125.1 (C 7,14 ), 124.1 (C 5,16 ), 82.2 (C 17 ), 71.6 (C 18,21 ), 69.9 (C 22−26 ), 69.0 (C 19,20 ), 46.4 (C 10 ), 39.6 (C 9 ).…”

Section: Organometallicsmentioning

confidence: 99%

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Diels–Alder Reactions of 9-Ferrocenyl- and 9,10-Diferrocenylanthracene: Steric Control of 9,10- versus 1,4-Cycloaddition

2013

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Cycloadditions of benzynes, N-methyl-or Nphenylmaleimide, dimethyl acetylenedicarboxylate, and benzoquinone to 9-ferrocenylanthracene (1) and 9,10-diferrocenylanthracene (2) are described. Benzyne and 3-fluorobenzyne add to 1 and 2 to form the corresponding 9-ferrocenyl-or 9,10-diferrocenyltriptycenes; in contrast, bulkier benzynes such as 3-trifluoromethylbenzyne preferentially add to 2 across C 1 and C 4 to form 6,11-diferrocenyl-5,12-etheno-5,12-dihydrotetracenes. The maleimides undergo Diels−Alder reactions with 1 to form the 9-ferrocenylbarrelenes 10 and 11, but cycloaddition to 2 occurs not only across C 9 and C 10 to form the barrelene 13 but also across C 1 and C 4 to yield ethenoanthracenes as both endo and exo adducts, 14 and 15, respectively. Likewise, DMAD forms 11,12-dicarbomethoxy-9-ferrocenylbarrelene (16) with 1 but reacts with 2 by addition across C 1 and C 4 to form 17. Hydrolysis of 16 cleaves only the ester distant from the ferrocenyl group. Treatment of the Diels−Alder adduct 20 of 9-ferrocenylanthracene (1) and benzoquinone with base and RX (R = Me, Et, CH 2 OMe, CH 2 CO 2 Me) yields the corresponding 1,4-dialkoxy-9-ferrocenyltriptycenes 22−25. The factors influencing the regiochemistry of the cycloadditions are discussed, and several examples of each reaction type have been characterized by X-ray crystallography.

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Section: ■ Discussionmentioning

confidence: 99%

Section: Organometallicsmentioning

confidence: 99%

Section: Organometallicsmentioning

confidence: 99%

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Diels–Alder Reactions of 9-Ferrocenyl- and 9,10-Diferrocenylanthracene: Steric Control of 9,10- versus 1,4-Cycloaddition

2013

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“…Typically, benzyne adds to 9,10-dimethylanthracene to form exclusively the electronically favoured 9,10-dimethyltriptycene, thus generating three aromatic systems. In contrast, with 9,10-diphenylanthracene, benzyne adds to the 1,4 rather than the 9,10-positions by a factor of 93:7 [28].…”

Section: Cycloaddition Reactions Of Mono-and Di-ferrocenyl Anthracenesmentioning

confidence: 94%

Palladium-Catalysed Coupling Reactions En Route to Molecular Machines: Sterically Hindered Indenyl and Ferrocenyl Anthracenes and Triptycenes, and Biindenyls

McGlinchey

Nikitin

2020

Molecules

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Pd-catalysed Stille and Suzuki cross-couplings were used to prepare 9-(3-indenyl)-, 6, and 9-(2-indenyl)-anthracene, 7; addition of benzyne led to the 9-Indenyl-triptycenes, 8 and 9. In 6, [4 + 2] addition also occurred to the indenyl substituent. Reaction of 6 through 9 with Cr(CO)6 or Re2(CO)10 gave their M(CO)3 derivatives, where the Cr or Re was complexed to a six- or five-membered ring, respectively. In the 9-(2-indenyl)triptycene complexes, slowed rotation of the paddlewheel on the NMR time-scale was apparent in the η5-Re(CO)3 case and, when the η6-Cr(CO)3 was deprotonated, the resulting haptotropic shift of the metal tripod onto the five-membered ring also blocked paddlewheel rotation, thus functioning as an organometallic molecular brake. Suzuki coupling of ferrocenylboronic acid to mono- or dibromoanthracene yielded the ferrocenyl anthracenes en route to the corresponding triptycenes in which stepwise hindered rotations of the ferrocenyl groups behaved like molecular dials. CuCl2-mediated coupling of methyl- and phenyl-indenes yielded their rac and meso 2,2′-biindenyls; surprisingly, however, the apparently sterically crowded rac 2,2′-Bis(9-triptycyl)biindenyl functioned as a freely rotating set of molecular gears. The predicted high rotation barrier in 9-phenylanthracene was experimentally validated via the Pd-catalysed syntheses of di(3-fluorophenyl)anthracene and 9-(1-naphthyl)-10-phenylanthracene.

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“…One way to suppress the scrambling process is to use a sterically hindered dipyrromethane. 15 In our case, however, the functional group on the aryl substituent used to induce steric hindrance has to be carefully chosen since it must not preclude the introduction of fullerenes inside the host's pocket. For this reason, we chose 5-(2,6-dichlorophenyl)dipyrromethane (1) 12 over the bulkier 5-mesityldipyrromethane because the van der Waals radii of the chloride atom is smaller than that of the methyl group and should cause less steric hindrance towards further complexation with fullerenes.…”

Section: Synthesis Of Strapped Porphyrinsmentioning

confidence: 99%

New strapped porphyrins as hosts for fullerenes: synthesis and complexation study

Giguère

Morin

2012

Org. Biomol. Chem.

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New strapped porphyrin-based hosts with different π-conjugated moieties and linkers have been prepared and their ability to bind with fullerenes was studied in dilute solution. We found that the ability of these hosts to bind with fullerenes strongly depends on their chemical nature and more precisely on the substitution pattern of the porphyrin deck. As expected, the more electron-rich hosts containing either an exTTF or a porphyrin unit as the strap bind fullerenes more efficiently with association constants of up to 3.9 × 10(5) M(-1). The results clearly demonstrate the potential of such hosts as a supramolecular scaffold for surface immobilization of pristine fullerenes.

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Reactivity of benzyne toward anthracene systems

Cited by 48 publications

References 0 publications

Diels–Alder Reactions of 9-Ferrocenyl- and 9,10-Diferrocenylanthracene: Steric Control of 9,10- versus 1,4-Cycloaddition

Diels–Alder Reactions of 9-Ferrocenyl- and 9,10-Diferrocenylanthracene: Steric Control of 9,10- versus 1,4-Cycloaddition

Palladium-Catalysed Coupling Reactions En Route to Molecular Machines: Sterically Hindered Indenyl and Ferrocenyl Anthracenes and Triptycenes, and Biindenyls

New strapped porphyrins as hosts for fullerenes: synthesis and complexation study

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