Oxidative aromatische Kupplung und Scholl‐Reaktion im Vergleich

Grzybowski, Marek; Skonieczny, Kamil; Butenschön, Holger; Gryko, Daniel T.

doi:10.1002/ange.201210238

Cited by 237 publications

(33 citation statements)

References 257 publications

(168 reference statements)

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“…Thea mino-substituted DBU and the nitro-substituted DBP were converted into alkynes 1 and 3 ( Figure 1) through aseries of common organic transformations (see Figure S1 in the Supporting Information). A[ 2 + +2+ +2] cyclotrimerization of 1 or 3,c atalyzed by Co 2 (CO) 8 in dioxane at 120 8 8C, produced the hexaaryl benzene precursor 2 or 4,w hich was amenable to further dehydrocyclization [17] to give the desired product N-H7H or C-H7H by forming six new CÀCbonds (Figure 1, cyan) under specific oxidative conditions.N otably,S choll oxidation of apolyphenylene precursor failed to provide C-H7H,although this method was successful for the production of the methoxysubstituted H7H. [9a] Thet ransformation of 2 into N-H7H was an extremely demanding reaction.…”

Section: Resultsmentioning

confidence: 99%

A Nitrogen‐Doped Hexapole [7]Helicene versus Its All‐Carbon Analogue

et al. 2019

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Tw os ynthetic nanographenes (NGs), N-H7H and C-H7H,w ere prepared. N-H7H is doped with nitrogen, and C-H7H is the all-carbon analogue.B oth are hexapole [7]helicenes (H7Hs), and their structures were identified by singlecrystal X-raydiffraction. Sharp contrasts in absorption ( abs l max , 683 vs.5 93 nm), emission ( em l max ,8 94 vs.7 77 nm), and electrochemical behavior ( ox E 1 ,0.28 vs.0.53 V) were observed between N-H7H and C-H7H,a nd the origin of these differences was rationalized by theoretical calculations.S tudies on N-H7H and C-H7H set ac lear example to elucidate the remarkable effects of N-doping on the physical properties of NGs.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

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Section: Resultsmentioning

confidence: 99%

A Nitrogen‐Doped Hexapole [7]Helicene versus Its All‐Carbon Analogue

et al. 2019

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“…[15] In the literature there is ap lethorao fo xidative dehydrogenative aromatic couplings which operate througharadical mechanism in the presence of either Lewis or Brønst-ed acids. [28] In relation to this,t he characterisation of oACs hows that there are both quinone type C=O and acidic CO 2 Hg roups on the carbon material. Althought he acid groups were not necessary for the indole homocouplings,t he benzofuran homocoupling can also be mediated either with DDQ or oACa sa n oxidanti nt he presenceo fM sOH additive.…”

Section: Reaction Mechanismmentioning

confidence: 91%

Carbocatalysed Oxidative CC Homocouplings of Benzo‐Fused Heterocycles

et al. 2015

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Appropriate and fine-tuned treatments of amorphous carbon (AC) involving aqua regia or concentrated HNO 3 leadt oo xidised carbon materials (oAC) which are able to catalyse 2,2'-a nd 3,3'-homocouplings of various functionalised indoles with outstandinga ctivity.T his newly developed carbocatalysed C sp 2 À C sp 2 bondf ormation can be achieved under mild thermalc onditions.T he study on the scope of the reactionr evealed that the reaction can be extended to the homocoupling of other substrates of high synthetic interest such as 2-naphthol, 2-functionalised benzofurans and benzothiofurans. Thec haracterisation of oACw ith XPS together with ad hoc experiments aimeda tb locking the active site revealed that the presence and distribution of C=Of unctionalities is critical and correlates well with the catalytic activity.S uch experiments provide solid support for elucidationo ft he mechanism, suggesting aq uinone nature of the active C= Og roups,w hich are spontaneously regenerated by oxygen. This is confirmed by the fact that 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is able to promote the coupling in as toichiometricf ashion.

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“…Previously,w eh ave attempted to synthesize 1 via an oxidative cyclization (Scholl reaction) [10] of pentakis(biphenyl-2-yl)corannulene (2). However,u nder these reaction conditions,b oth the 6-membered and the 7-membered rings were generated to form warped nanographene 3.…”

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confidence: 99%

A Quintuple [6]Helicene with a Corannulene Core as a C₅‐Symmetric Propeller‐Shaped π‐System

et al. 2018

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The synthesis and structural analysis of a quintuple [6]helicene with a corannulene core is reported. The compound was synthesized from corannulene in three steps including a five-fold intramolecular direct arylation. X-ray crystallographic analysis revealed a C -symmetric propeller-shaped structure and one-dimensional alignment in the solid state. The enantiomers of the quintuple [6]helicene were successfully separated by HPLC, and the chirality of the two fractions was identified by CD spectroscopy. A kinetic study yielded a racemization barrier of 34.2 kcal mol , which is slightly lower than that of pristine [6]helicene. DFT calculations indicate a rapid bowl-to-bowl inversion of the corannulene moiety and a step-by-step chiral inversion pathway for the five [6]helicene moieties.

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Oxidative aromatische Kupplung und Scholl‐Reaktion im Vergleich

Cited by 237 publications

References 257 publications

A Nitrogen‐Doped Hexapole [7]Helicene versus Its All‐Carbon Analogue

A Nitrogen‐Doped Hexapole [7]Helicene versus Its All‐Carbon Analogue

Carbocatalysed Oxidative CC Homocouplings of Benzo‐Fused Heterocycles

A Quintuple [6]Helicene with a Corannulene Core as a C₅‐Symmetric Propeller‐Shaped π‐System

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Oxidative aromatische Kupplung und Scholl‐Reaktion im Vergleich

Cited by 237 publications

References 257 publications

A Nitrogen‐Doped Hexapole [7]Helicene versus Its All‐Carbon Analogue

A Nitrogen‐Doped Hexapole [7]Helicene versus Its All‐Carbon Analogue

Carbocatalysed Oxidative CC Homocouplings of Benzo‐Fused Heterocycles

A Quintuple [6]Helicene with a Corannulene Core as a C5‐Symmetric Propeller‐Shaped π‐System

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A Quintuple [6]Helicene with a Corannulene Core as a C₅‐Symmetric Propeller‐Shaped π‐System