Dioxygen‐Triggered Transannular Dearomatization of Benzo[5]helicene Diols: Highly Efficient Synthesis of Chiral π‐Extended Diones

Shen, Yun; Lu, Haiyan; Chen, Chuan‐Feng

doi:10.1002/anie.201400486

Cited by 30 publications

(12 citation statements)

References 60 publications

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“…The remained chirality in the reactions indicated the phenyl groups at 1,16-positon of (À )-(P)-6 and (+)-(M)-6 could prevent racemization effectively. [13] Therefore, a conclusion could be drawn that the absolute configuration of (À )-7 was R,R central chirality, while (+)-7 possessed S,S central chirality. The enantiomers (À )-7 and (+)-7 showed identical UV-Vis spectra ( Figure 1a) and mirror-imaged CD spectra (Figure 1b).…”

Section: Synthesis Structures and Properties Of Enantiomeric Dibromomentioning

confidence: 99%

“…After the reaction was complete (30 min) monitoring by TLC, saturated NH 4 Cl aqueous solution (20 mL) was added, and the subsequent mixture was stirred for 5 min. 13 C NMR (126 MHz, CDCl 3 ): δ 151. M. p.: 168-170°C.…”

Section: Compound Rac-2mentioning

confidence: 99%

“…[11] During the past years, we have been focusing on developing efficient synthetic strategies for the functionalized helicene derivatives, and exploring their potential applications in materials science. [13] However, it was found that this method could not be applied in oxidative dearomatization reaction of tetrahydro [5]helicene diols because they are stable under the tested conditions. [13] However, it was found that this method could not be applied in oxidative dearomatization reaction of tetrahydro [5]helicene diols because they are stable under the tested conditions.…”

Section: Introductionmentioning

confidence: 99%

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One‐Pot Oxidative Aromatization and Dearomatization of Tetrahydro[5]helicene Diols: Synthesis, Structure, Photophysical and Chiroptical Properties of Chiral π‐Extended Diones

Fang

Lin

et al. 2018

Asian J Org Chem

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One-pot oxidative aromatization and dearomatization (OADA) reactions of tetrahydro [5]helicene diols with 2,3dichloro-5,6-dicyanobenzoquinone (DDQ) as the oxidant were demonstrated, which provided an efficient method for the synthesis of chiral π-extended diones. Consequently, a series of enantiomeric π-extended diones were obtained in high yields by a one-pot OADA of dibromo-substituted tetrahydro[5]helicene diols, and then followed by Suzuki-Miyaura cross-coupling reactions, or vice versa. The absolute configurations of the chiral diones were determined by their CD spectral analysis and X-ray structure of the dibromosubstituted dione. Moreover, the enantiomeric diones also exhibited mirror-imaged CD spectra and showed mirrorimaged circularly polarized luminescence (CPL) properties with the luminescence dissymmetry factor up to � 9.0 × 10 À 4 . It was further found that the chiral diones showed different fluorescence spectra, and substituent-dependent fluorescence quantum yields. For the chiral diones with strong electron-donating groups, high fluorescence quantum yields of up to 30.3% were found. Such chiral diones with high fluorescence quantum yields and significant CPL properties might have potential applications not only in asymmetric catalytic synthesis, but also chiroptical materials.[a] L. Fang, Dr.

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Section: Synthesis Structures and Properties Of Enantiomeric Dibromomentioning

confidence: 99%

Section: Compound Rac-2mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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One‐Pot Oxidative Aromatization and Dearomatization of Tetrahydro[5]helicene Diols: Synthesis, Structure, Photophysical and Chiroptical Properties of Chiral π‐Extended Diones

Fang

Lin

et al. 2018

Asian J Org Chem

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“…[11a] Despitet he rapid development of helicenes in both synthesis and applications in recent years, there are still few reports on functionalization on positions near the fjord region of [5]helicenes for great steric hindrance ( Figure 1). [11,12] To explore their practical applicationsi nc hiral recognition,c hiral assembly,a nd chiral organic functionalm aterials,u ndoubtedly,i ti sv ery important and meaningful to develop new and efficient routes to functionalize on the interior of the helix and synthesize optically pure and stable [5]helicene derivatives.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Structures, Resolution, and Chiroptical Properties of 1,16‐Diaryl‐Substituted Benzo[5]helicene Derivatives

Lin

Fang

et al. 2016

Chemistry An Asian Journal

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An efficient route to the synthesis of benzo[5]helicene derivatives functionalized on the interior side of the helix was developed, and resulted in a series of 1,16-diaryl-substituted benzo[5]helicene derivatives starting from easily available 7-methoxytetralone. X-ray crystal structures showed that the benzo[5]helicene derivatives had highly helical, twisted structures, and could all create hierarchical packing architectures with alternating P and M layers in the solid state. Moreover, seven pairs of enantiomers based on 1,16-diaryl-substituted benzo[5]helicene derivatives were also obtained by efficient resolution through HPLC with semipreparative chiral columns. The enantiomers all showed clear mirror-image circular dichroism (CD) spectra and high specific optical rotations, and their absolute configurations were determined by X-ray crystallography. Interestingly, a helical nanotubular structure was formed by the self-assembly of one enantiomer through halogen bonding. Furthermore, the enantiomers were found to have high racemization barriers and thermostability, which might be caused by the introduction of aryl substituents at the C1(C16) position.

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“…[1][2][3][4][5] Thus, much affords have been made towards controlling and understanding chirality in chemical synthesis and material design. [10][11][12][13][14][15][16][17] More interesting, the dissymmetric backbone makes helicenes and their derivatives applications in many fields (e.g. [6][7][8][9] Steric hindrance interaction between terminal aromatic rings endows helicenes with helical chirality.…”

Section: Introductionmentioning

confidence: 99%

Photophysical properties of quinoxaline-fused [7]carbohelicene derivatives

Liu

Pan

et al. 2015

RSC Adv.

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Helicene and its derivatives have received much attention as the candidates of organic photoelectronic material. Recently, novel quinoxaline-fused [7]carbohelicene derivatives exhibit unique structural and photophysical properties, especially in the crystal states. However, their structure-property relationships have not been fully understood from the micromechanism, which is also important to further improve their performance. Here, the electronic transition, electronic circular dichroism (CD), second-order nonlinear optical (NLO) response and charge transport properties of five quinoxaline-fused [7]carbohelicene derivatives have been investigated based on density functional theory calculations. The experimental UV-Vis/CD spectra of the studied compounds were well reproduced by our calculations. Thus, we can assign their electron transition properties and absolution configurations (ACs) with high confidence. It is found that CD bands of quinoxaline-fused [7]carbohelicene derivatives mainly originate from exciton coupling between quinoxaline, phenyl or 4-methoxyphenyl and [7]carbohelicene, which is in sharp contrast to [7]carbohelicene. More interestingly, these derivatives possess large first hyperpolarizability values. For example, the βHRS value of compound 6 is 32.96 × 10 −30 esu, which is about 190 times larger than that of the organic urea molecule. The bandwidth of valence band of compound 2 is comparable to that of conduction band and slightly larger than that of tris(8-hydroxyquinolinato)aluminium. This means that compound 2 is the potential candidate as ambipolar charge transport material. Please do not adjust marginsPlease do not adjust margins modulates the LUMO energy level. As a consequence, LUMO energy of compound 2 is much lower than that of compound 1 (Table S6), which leads to the smaller energy gap (Eg) for compound 2. Moreover, the main electron transitions characters are of charge transfer from quinoxaline to [7]carbohelicene and vice versa (Fig. 3). On the basis of above analysis, it is found that involvement of quinoxaline unit not only modulates the electron absorption wavelength but also alter the electron transition property. Compounds 3 and 4 also exhibit four absorption bands, which is similar to those of compound 2. In other words, the substituent effect of phenyl or 4-methoxyphenyl group on the UV-Vis spectra of compound 2 is not great. It is noted that some of the molecular orbitals involved in these transitions partially located on the phenyl or 4-methoxyphenyl group. Fig. 2Calculated UV-Vis (left) and CD (right) spectra in gas phase of 1, 2, 3 and 4 at the TDB3LYP/6-31+G(d) level of theory along with the experimental spectra (red dashed line).

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Dioxygen‐Triggered Transannular Dearomatization of Benzo[5]helicene Diols: Highly Efficient Synthesis of Chiral π‐Extended Diones

Cited by 30 publications

References 60 publications

One‐Pot Oxidative Aromatization and Dearomatization of Tetrahydro[5]helicene Diols: Synthesis, Structure, Photophysical and Chiroptical Properties of Chiral π‐Extended Diones

One‐Pot Oxidative Aromatization and Dearomatization of Tetrahydro[5]helicene Diols: Synthesis, Structure, Photophysical and Chiroptical Properties of Chiral π‐Extended Diones

Synthesis, Structures, Resolution, and Chiroptical Properties of 1,16‐Diaryl‐Substituted Benzo[5]helicene Derivatives

Photophysical properties of quinoxaline-fused [7]carbohelicene derivatives

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