Synthesis of novel 4,5‐diazafluoren‐9‐one derivatives and theoretical study of 3+2 cycloaddition reactions

Danac, Ramona; Druţă, I.; Rotaru, Alexandru; Ghirvu, C.; Constantinescu, Mircea

doi:10.1002/jhet.5570410621

Cited by 9 publications

(2 citation statements)

References 16 publications

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“…20 The heteroaromatic N-ylides 5 were generated in situ, by action of triethylamine on bromides 4. 1,3-Dipolar cycloaddition reaction of N-ylides 5 with dimethyl, diethyl or diisopropyl acetylenedicarboxylate in dichloromethane at room temperature gave a mixture consisting of dihydroderivatives 7 along with variable amounts of aromatized pyrrolodiazafluoren-5-ones 8.…”

Section: Resultsmentioning

confidence: 99%

Helical chirality of pyrrolo[1,2-a][4,5]diazafluoren-5-one derivatives

Dumitraşcu¹,

Caira²,

Vasilescu³

et al. 2007

Arkivoc

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The treatment of the N-phenacyl-4,5-diazafluorenium-9-one bromides 4a,b and the diesters of acetylenedicarboxylic acid with Et 3 N in methylene chloride at room temperature gave trans-9,10-dihydro-pyrrolo[1,2-a][4,5]diazafluoren-5-one derivatives 7 along with the corresponding aromatized compounds 8. The non-planarity of the diethyl (8c,e) and diisopropyl (8d,f) pyrrolodiazafluorenone esters was deduced by H-NMR spectroscopy. The 1,3-dipolar cycloaddition between diazafluorenonium N-ylides, generated from 4, and an activated olefinic dipolarophile (acrylonitrile) is reported for the first time. The optical properties of pyrrolodiazafluorenone 8 were also investigated.

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Section: Resultsmentioning

confidence: 99%

Helical chirality of pyrrolo[1,2-a][4,5]diazafluoren-5-one derivatives

Dumitraşcu¹,

Caira²,

Vasilescu³

et al. 2007

Arkivoc

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“…To complete oxidative aromatization tetrakispyridino Co(II) dichromate (TPCD) was used (Scheme 27). [79,80] Similar reaction of 1-(3-nitrophenacyl)-1,10-phenanthrolinium ylide with activated alkynes (acetylene dicarboxylates and propiolates) gave pyrrolo[1,2-a][1,10]phenanthrolines 98 and 99. [81] An efficient the BF 3 .…”

Section: 3-dipolar Cycloaddition and Diels-alder Reactionmentioning

confidence: 99%

Alkyne‐Based Syntheses of Carbo‐ and Heterohelicenes

Gulevskaya

Tonkoglazova

2022

Adv Synth Catal

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[n]Helicenes are polycyclic aromatic molecules in which n ortho‐condensed benzene or other aromatic rings give rise to helical chiral and highly conjugated structures. The unique screw shape, helically extended π‐system and intriguing electronic and chirooptical properties of these molecules have attracted scientific interest for decades. The applications of helicenes have now expanded into several fields including material science, nanoscience, biochemistry, supramolecular and polymer chemistry. Despite the great theoretical and practical interest in helicenes, their synthesis remains a challenge. Among synthetic approaches to helicenes, alkyne cyclizations have great potential, since carbon‐rich high‐energy alkynes can form aromatic rings via cycloisomerizations. These processes are atom‐economic. In addition, alkyne reactions are highly favorable thermodynamically. This review focuses on alkyne‐based syntheses of carbo‐ and heterohelicenes (2000–2022). These syntheses are obviously multistage. In the review, they are systematized in terms of the key step leading to the formation of a helical shape. The methods are grouped into two categories: (a) metal‐free syntheses and (b) transition‐metal‐catalyzed syntheses. This division is very arbitrary, since catalytic Sonogashira and Suzuki‐Miyaura reactions and others are often used to prepare starting materials in the syntheses of the first group. Most of the publications on the topic are related to transition‐metal‐catalyzed syntheses of helicenes.

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