Electron donor-acceptor photochemistry of 1-cyano-naphthalene with norbornadiene: Stereospecific regiorandom [2 + 2] cycloaddition

Weng, Hengxin; Roth, Heinz D.

doi:10.1016/0040-4039(96)01004-0

Cited by 13 publications

(9 citation statements)

References 19 publications

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“…In polar solvents, the reaction is more selective, favoring anti-addition to the substituted ring. 12 Some features of the adducts between 1 CNN* and N differ from those with other donors. The highly stereospecific exo-addition to N is reminiscent of the stereospecific attack of methanol on N Á .…”

Section: Discussionmentioning

confidence: 96%

“…R = CH 3 O), resulting in a variety of products. 10,12,19 The driving force for electron transfer [equation (2)] from N to 1 CNN* is different from that to 1 DCB*. The free energy of radical ion pair formation is given by the excited state energy, E (0,0) , the reduction and oxidation potentials of the reagents, E (AÀ/A) and E (D/D) , and a term accounting for ion pairing which, in polar solvents, has a value of ca 0.06 eV:…”

Section: Discussionmentioning

confidence: 98%

“…12 The discrepancies with earlier results 11 are ascribed to advances in separation techniques during the intervening years.…”

Section: Introductionmentioning

confidence: 88%

“…Four [2 2]-cycloadducts (4-7) were described earlier; 12 the minor product (8) apparently resulted from All cycloaddition products show four features characteristic for the 5,6-disubstituted norbornene unit. 13 First, two resonances (d,d; ca 5.8-6.2 ppm, J % 6, 3 Hz), sometimes overlapping, are typical for the olefinic norbornene protons (H 2',3' ).…”

Section: Cycloaddition Productsmentioning

confidence: 98%

“…Similarly to the [2 2]-adducts 4-7, their NMR spectra show the general features characteristic for a 5,6-disubstituted norbornene unit. 12 The coupling patterns of the resonances representing H 5' and H 6' (J 5n-6x = 3-6 Hz, J 5n-4`1 Hz, J 1-6x % 3 Hz) identify the adducts as 6-endo-substituted 5-exo-methoxynorbornenes.…”

Section: Cycloaddition Productsmentioning

confidence: 99%

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Stereospecific nucleophilic trapping of encounter complexes between photoexcited 1-cyanonaphthalene and norbornadiene

Weng

Roth

1998

J. Phys. Org. Chem.

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Photo-induced electron donor-acceptor reactions between 1-cyanonaphthalene (CNN) and norbornadiene (N) generate products of several structure types. Methanol adducts (1-3) formed in polar solvents are rationalized via the radical cation, N Á , and stereospecific (exo-) nucleophilic attack by methanol. In less polar solvents, CNN and N form [2 + 2]-cycloadducts, exclusively on the exo-face of N. In non-polar solvents containing methanol, CNN, N and methanol combine to form 1:1:1 adducts, containing the sensitizer on the endo-and the methoxy groups on the exo-face. The formation of these products is rationalized via the trapping of encounter complexes of different geometries. Any rearrangement of the norbornenyl system can be eliminated, since neither tricyclyl nor 7-methoxynorbornenyl structures are formed. Apparently, the alcohol captures an endo-encounter complex of CNN and N by attack from the exo-face, similar to the attack of methanol on N Á .

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Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 98%

“…12 The discrepancies with earlier results 11 are ascribed to advances in separation techniques during the intervening years.…”

Section: Introductionmentioning

confidence: 88%

Section: Cycloaddition Productsmentioning

confidence: 98%

Section: Cycloaddition Productsmentioning

confidence: 99%

See 3 more Smart Citations

Stereospecific nucleophilic trapping of encounter complexes between photoexcited 1-cyanonaphthalene and norbornadiene

Weng

Roth

1998

J. Phys. Org. Chem.

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Electron transfer photochemistry of 7-(spirocyclopropane)quadricyclane: capture of a radical cation and sequential cyclopropylcarbinyl rearrangements

McIlroy

Weng

Roth

1997

J. Phys. Org. Chem.

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The electron transfer photo-sensitized reaction of 7-(spirocyclopropane)quadricyclane (1) with methanol produces two rearranged mono-methanol adducts, 2 and 3, and a bis-methanol adduct, 4. The products reveal that 1 ᭹ + reacts by stereo-and regiospecific attack of methanol on one trisubstituted cyclopropane ring. The resulting free radical rapidly undergoes one or two (consecutive) cyclopropylcarbinyl to butenyl rearrangements. The mono-adducts are formed by net hydrogen abstraction, the di-adduct via a (secondary) electron transfer reaction of 3.

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Synthesis of 3‐Oxatricyclo[7.2.0.0^1,5]undeca‐7,10‐dienes through Intramolecular Photocycloaddition Reactions of Alkenes to 1,8 a‐Position of Naphthalene Ring

et al. 2022

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Benzene solutions of 1-(5-aryl-2-oxapent-4-enyl)-2-cyanonaphthalenes 6 were irradiated with a high-pressure mercury lamp for 20 h to give 3-oxatricyclo[7.2.0.0 1,5 ]undecadienes 7 in good yields. In all cases, the trans isomer was preferentially obtained. Sensitization and quenching experiments showed that the reaction proceeds via an excited singlet state. When a dichloromethane solution of 6 was irradiated for only 1 h, an eightmembered ring compound 8 was obtained as an intermediate. When the obtained 8 was irradiated, the final product 7 was produced. The long wavelength absorption of 6 originates from the 2-cyanonaphthalene chromophore, indicating that the reaction is initiated by photoexcitation of the naphthalene ring. In addition, the fluorescence of 6 was intramolecularly quenched, and a weak intramolecular exciplex emission was observed at 400-550 nm. In this reaction, after photoexcitation of 6, a [2 + 2] photocycloadduct is formed at the 1,8a-position of the naphthalene ring via an intramolecular singlet exciplex, followed by thermal ring-opening and 4π disrotatory ringclosure leads to 7.

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Electron donor-acceptor photochemistry of 1-cyano-naphthalene with norbornadiene: Stereospecific regiorandom [2 + 2] cycloaddition

Cited by 13 publications

References 19 publications

Stereospecific nucleophilic trapping of encounter complexes between photoexcited 1-cyanonaphthalene and norbornadiene

Stereospecific nucleophilic trapping of encounter complexes between photoexcited 1-cyanonaphthalene and norbornadiene

Electron transfer photochemistry of 7-(spirocyclopropane)quadricyclane: capture of a radical cation and sequential cyclopropylcarbinyl rearrangements

Synthesis of 3‐Oxatricyclo[7.2.0.0^1,5]undeca‐7,10‐dienes through Intramolecular Photocycloaddition Reactions of Alkenes to 1,8 a‐Position of Naphthalene Ring

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Electron donor-acceptor photochemistry of 1-cyano-naphthalene with norbornadiene: Stereospecific regiorandom [2 + 2] cycloaddition

Cited by 13 publications

References 19 publications

Stereospecific nucleophilic trapping of encounter complexes between photoexcited 1-cyanonaphthalene and norbornadiene

Stereospecific nucleophilic trapping of encounter complexes between photoexcited 1-cyanonaphthalene and norbornadiene

Electron transfer photochemistry of 7-(spirocyclopropane)quadricyclane: capture of a radical cation and sequential cyclopropylcarbinyl rearrangements

Synthesis of 3‐Oxatricyclo[7.2.0.01,5]undeca‐7,10‐dienes through Intramolecular Photocycloaddition Reactions of Alkenes to 1,8 a‐Position of Naphthalene Ring

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Synthesis of 3‐Oxatricyclo[7.2.0.0^1,5]undeca‐7,10‐dienes through Intramolecular Photocycloaddition Reactions of Alkenes to 1,8 a‐Position of Naphthalene Ring