Die Synthese ungewöhnlicher organischer Verbindungen aus Azoalkanen

Adam, Waldemar; Lucchi, Ottorino De

doi:10.1002/ange.19800921006

Cited by 67 publications

(4 citation statements)

References 196 publications

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“…The photochemisty of the azo chromophore has long been the subject of extensive investigation . Two prototypes are 2,3-diazabicyclo[2.2.1]hept-2-ene ( DBH ) and 2,3-diazabicyclo[2.2.2]oct-2-ene ( DBO ), which serve to exemplify succinctly the distinct photophysical and photochemical properties of cyclic azoalkanes in general.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast to the diazabicyclo[2.2.1]hept-2-ene ( DBH ), which eliminates molecular nitrogen smoothly upon photoexitation (Φ r ca. 1 1a, ), the photoreactivity of DBO is extraordinary low (Φ r = 0.022 in MeCN) and, therefore, the latter constitutes a photopersistent azoalkane. Besides the investigation of the photophysical and photochemical properties of the azo chromophore, some work has been conducted in the past in regard to the photoelectron-transfer (PET) chemistry of azoalkanes.…”

Section: Introductionmentioning

confidence: 99%

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Photoreduction of Polycyclic DBO-Type Azoalkanes with Amines to Hydrazine Products

and

Nikolaus

2000

J. Am. Chem. Soc.

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The n,π*-singlet-excited polycyclic, α-substituted DBO-type azoalkanes 1 are reduced by amines to form the corresponding hydrazines 2 as photoreduction products in competition to denitrogenation to the bicyclo[2.2.0]hexane photoproducts 3. The photophysical, photochemical, and electrochemical properties of the azoalkane determine the product ratio of the hydrazine 2 versus the bicyclo[2.2.0]hexane 3. The quantum yields of the photoreduction are quite low (<0.1), for which efficient deactivation of the singlet excited state through charge transfer is postulated. The charge transfer in the exciplex between the azoalkane and the amine promotes the hydrogen abstraction of the α-CH bond from the amine by the azoalkane and, thus, facilitates its photoreduction, a general photochemical process applicable to singlet- as well as triplet-excited azoalkanes.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Photoreduction of Polycyclic DBO-Type Azoalkanes with Amines to Hydrazine Products

and

Nikolaus

2000

J. Am. Chem. Soc.

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“…0 --2% 2 7 0 + g? 0 14 15 (9) The situation is, however, quite different with PTAD as dienophile, since it is sufficiently reactive to cycloadd with all substrates investigated here. Thus, the trienone 7 gives only the bicyclic adduct 11 with PTAD.…”

Section: Discussion Of the Resultsmentioning

confidence: 88%

ChemInform Abstract: (4 + 2)‐CYCLOADDITION OF SINGLET OXYGEN AND PHENYLTRIAZOLINEDIONE WITH BICYCLO(6.1.0)NONA‐2,4,6‐TRIENE AND DERIVATIVES

Adam¹,

Cueto²,

Lucchi³

1982

Chemischer Informationsdienst

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“…15 (9) The situation is, however, quite different with PTAD as dienophile, since it is sufficiently reactive to cycloadd with all substrates investigated here. Thus, the trienone 7 gives only the bicyclic adduct 11 with PTAD.…”

Section: Discussion Of the Resultsmentioning

confidence: 90%

[4 + 2]‐Cycloaddition of Singlet Oxygen and Phenyltriazolinedione with Bicyclo[6.1.0]nona‐2,4,6‐triene and Derivatives

1982

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The dienic reactivity of the bicyclononatrienes l a ([4.3.0]-isomer) and 1 b ([6.1 .O]-isomer) and its oxa-derivative 6 (cyclooctatetraene epoxide) as well as 1,3,5-cyclooctatrienone (7), towards singlet oxygen ('0,) and phenyl-l,2,4-triazoline-3,5-dione (PTAD) as dienophiles has been investigated. Except for l a , which affords the endoperoxide 9a in 60% yield, the remaining substrates l b , 6 , and 7 do not react with '0,. With PTAD l a , l b , 6 , and 7 afford the urazoles 10a, 8b, 1212, and 11, respectively. Unusual is the fact that the bicyclo[6. products 2 a -c (Eq. 1). The valence isomer l b has been prepared some time ago'); its dienic reactivity has been investigated to some extent. For example, it was reported2a-c) that tetracyanoethylene gave the [2 + 21-cycloadduct 3 and the [4 + 21-cycloadduct 3c, while maleic anhydride afforded a mixture of the products 4a and 4c in 33% and 67%, respectively. Clearly, the [4 + 21-cycloadduct 4a must be derived from the valence isomer l a and the [4 + 21-cycloadducts 3c and 4c from l c in order to rationalize these results. Other dienophiles that have been employed include dimethyl acetyienedicarboxylatezd), chlorosulfonylisocyanateZe), and

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Die Synthese ungewöhnlicher organischer Verbindungen aus Azoalkanen

Cited by 67 publications

References 196 publications

Photoreduction of Polycyclic DBO-Type Azoalkanes with Amines to Hydrazine Products

Photoreduction of Polycyclic DBO-Type Azoalkanes with Amines to Hydrazine Products

ChemInform Abstract: (4 + 2)‐CYCLOADDITION OF SINGLET OXYGEN AND PHENYLTRIAZOLINEDIONE WITH BICYCLO(6.1.0)NONA‐2,4,6‐TRIENE AND DERIVATIVES

[4 + 2]‐Cycloaddition of Singlet Oxygen and Phenyltriazolinedione with Bicyclo[6.1.0]nona‐2,4,6‐triene and Derivatives

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