188-52-3

Usage

Uses

Used in Molecular Electronics:
(5)HELICENE is used as a component in molecular electronics for its unique helical structure and electronic properties, which can contribute to the development of new functional materials and chemical processes.
Used in Chiral Catalysis:
(5)HELICENE is used as a chiral catalyst to facilitate asymmetric reactions, taking advantage of its chirality to induce selectivity in chemical transformations.
Used in Optoelectronics:
(5)HELICENE is used as a material in optoelectronic devices due to its potential to manipulate light and its electronic properties, which can be harnessed for applications such as organic light-emitting diodes (OLEDs).
Used in Liquid Crystals:
(5)HELICENE is used as a chiral dopant in liquid crystals, where its helicity can influence the alignment and properties of the liquid crystal medium.
Used in Fluorescent Materials:
(5)HELICENE is used as a fluorescent material in organic light-emitting diodes (OLEDs), leveraging its optical properties to enhance the performance of these devices.

InChI:InChI=1/C22H14/c1-3-7-19-15(5-1)9-11-17-13-14-18-12-10-16-6-2-4-8-20(16)22(18)21(17)19/h1-14H

Upstream product

• 1608-30-6 1,4-distyrylbenzene 
• 139371-86-1 3,9,12-Tribromo-dibenzo[c,g]phenanthrene 
• 54130-90-4 2,2'-di(bromomethyl)-1,1'-binaphthalene 
• 161146-88-9 [1,1′-binaphthalene]-2,2′-dicarboxaldehyde 
• 181699-37-6 1,2,5,6-tetrahydro-dibenzo[c,g]phenanthrene-3,4-dicarboxylic acid-anhydride 
• 118-92-3 anthranilic acid 
• 211235-96-0 1,2-dihydro-3-vinyl-phenanthrene 
• 1250981-24-8 5,6,9,10-tetrahydropentahelicene-5,10-diyl diacetate 
• 583-53-9 2,3-dibromobenzene 
• 819867-23-7 (2’,4’,6’-triisopropyl-[1,1’-biphenyl]-2-yl)-diphenylphosphine 
• 2633-08-1 cis-1,2-bis(2-naphthyl)ethylene 
• 139371-87-2 2-Bromo-1,4-bis-[(Z)-2-(4-bromo-phenyl)-vinyl]-benzene 
• 602-09-5 1,1'-bi-2-naphthol 
• 74866-28-7 2,2'-dibromo-1,1'-binaphthyl 

Downstream Products

• 191-24-2 Benzo[ghi]perylene 

Relevant academic research and scientific papers

Coordination chemistry of cyclopropenylidene-stabilized phosphenium cations: Synthesis and reactivity of Pd and Pt complexes

A straightforward synthesis of cyclopropenylidene-stabilized phosphenium cations 1 a-g through the reaction of [(iPr2N)2C 3+Cl]BF4 with secondary phosphines is described. Their donor ability was evalu

Stereochemical dichotomy in the Stevens rearrangement of axially twisted dihydroazepinium and dihydrothiepinium salts. A novel enantioselective synthesis of pentahelicene

Evidence is presented indicating that the stereochemistry of the Stevens rearrangement of the axially chiral onium salts 1a-d and 5 is dramatically structure-dependent. Thus, the binaphthyl ammonium salts (S)-(+)-1a-c react with a strong base with exclusive (100% de) formation of the corresponding rearranged amines (R,3R)-(+)-2a-c, demonstrating a complete transfer of the (S) axial dissymmetry/asymmetry into (R) asymmetry of the newly formed carbon center. Exactly opposite stereochemistry was established in an earlier study by Mislow of the biphenyl analogue (S)-(+)-5, yielding the rearranged products (S,9S)-(+)-6 and (R,9S)-(-)-7 with exclusive (S) configuration at the carbon center. Rearrangement of the sulfonium salt 1d is found to be intermediate between the two extremes, yielding a mixture of diastereoisomeric products 2d and 3d, which differ in configuration at the asymmetric carbon center. A direct proof is thus provided that two stereochemically different pathways can participate in the Stevens rearrangement. An explanation is suggested in terms of competition between suprafacial (concerted) and antarafacial (nonconcerted) mechanism.

Toward a visible light mediated photocyclization: Cu-based sensitizers for the synthesis of [5]helicene

A photochemical synthesis of [5]helicene employing a copper-based sensitizer 7 has been developed that avoids the disadvantages associated with the traditional UV light mediated method. The visible light mediated synthesis uses common glassware and a simple household light bulb without the competing formation of [2 + 2] cycloadducts, regioisomers, or the overoxidation product benzo[ghi]perylene 3. Preliminary results show that the reaction time can be significantly reduced through the use of a continuous flow strategy.

Helicene synthesis by Br?nsted acid-catalyzed cycloaromatization in HFIP [(CF3)2CHOH]

A facile synthesis of carbo- and heterohelicenes was achieved via tandem cycloaromatization of bisacetal precursors, which were readily prepared through C-C bond formation by Suzuki-Miyaura coupling. This cyclization was efficiently realized by a catalytic amount of trifluoromethanesulfonic acid (TfOH) in a cation-stabilizing solvent, 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), which readily allowed gram-scale syntheses of higher-order helicenes, double helical helicenes, and heterohelicenes.

Selective Vicinal Diiodination of Polycyclic Aromatic Hydrocarbons

Vicinally diiodinated polycyclic aromatic hydrocarbons (I2-PAHs) are accessible from the corresponding diborylated B2-PAHs through boron/iodine exchange. The B2-PAHs have been prepared via twofold electrophilic borylation reactions templated by a vicinally disilylated benzene. Our protocol is applicable to fluorenes, acenes, annulated acenes, oligoaryls, and even [5]helicene. Using B2-naphthalene as the example, we have shown that the reaction scope can, in principle, be expanded to include the synthesis of vicinally dibrominated and dihydroxylated PAHs. The usefulness of the building blocks provided by our method in the field of optoelectronic materials was demonstrated by the successful conversion of I2-fluoranthene to the analogous doubly alkynylated fluoranthene emitter.

Facile photochemical synthesis of 5,10-disubstituted [5]helicenes by removing molecular orbital degeneracy

Photocyclodehydrogenation is a key reaction to synthesize helicenes; however, because of overannulation, it is not applicable to the synthesis of [5]helicene. Introduction of a cyano group was found to remove the orbital degeneracy of the low-lying unoccupied MOs; consequently, the lowest excitation comprises a single transition involving the C2-antisymmetric MO. Therefore, the problematic overannulation can be effectively suppressed. Moreover, in combination with the Knoevenagel reaction, a one-pot synthesis of 5,10-dicyano[5]helicene with 67% yield was accomplished.

Synthesis of phenanthrenes by cationic chromium(III) porphyrin-catalyzed dehydration cycloaromatization

Readily available biphenyl derivatives with ortho oxirane moiety react in the presence of cationic chromiun(III) porphyrin catalyst to afford phenanthrenes. The reaction is considered to be triggered by activation of the oxirane moiety through coordination to the Lewis acidic cationic chromium to give aldehyde via 1,2-hydride shift, which reacts with arene through intramolecular electrophilic aromatic substitution and subsequent dehydration. The reaction allows constructing a variety of polycyclic aromatic and heteroaromatic compounds.

Rhodium(II)-catalyzed cyclization of bis(N-tosylhydrazone)s: An efficient approach towards polycyclic aromatic compounds

Ahead of the PAC: Polycyclic aromatic compounds (PACs) can be easily accessed by the combination of Suzuki-Miyaura cross-coupling and a [Rh 2(OAc)4]-catalyzed carbene reaction using easily available bis(N-tosylhydrazone)s as intermediates (see scheme; Ts=4-toluenesulfonyl). Copyright

Exploiting the π-acceptor properties of carbene-stabilized phosphorus centered trications [L3P] 3+: Applications in Pt(II) catalysis

Reaction of tris(dimethylaminocyclopropenium) substituted phosphine 1 with K2PtCl4 afforded the bench stable complex 3 which upon treatment with Ag[CB11H6Cl6] turned out to be an excellent catalyst for the transformation of a variety of ortho-biaryl substituted alkynes into polycyclic homo- and heteroarenes of different size, shape, and curvature through a 6-endo-dig cyclization. This constitutes the first example ever reported of using a P1-centered trication as ligand in catalysis. The strong π-acceptor character of 1 that derives from its three positive charges substantially increases the intrinsic π-acidity of Pt in complex 1?PtCl2 and dramatically enhances its ability to activate π-systems toward nucleophilic attack. As a consequence, a remarkable acceleration of the model transformation is observed when compared with other classical π-acceptor ligands such as P(OPh)3 or P(C 6F5)3. Moreover, the employment of 1 as ligand also expands the scope of this reaction to previously inaccessible substitution patterns. Kinetic studies and deuterium labeling experiments as well as density functional theory (DFT) calculations were performed in order to explain these findings.

A versatile synthesis of functionalized pentahelicenes

A general synthetic methodology for the preparation of functionalized (hetero)helicenes has been developed. It employs the sequence of a double propargyl organometallics (Li, Mg, Ga/In) addition to a tolan-2,2′- dialdehyde-type intermediate, a cobalt-catalyzed/cobalt-mediated [2 + 2 + 2] cycloisomerization of a triyne intermediate, and a double silica gel-assisted acetic acid elimination to receive pentahelicene, 1,14-diazapentahelicene, and 3,12-dichloro-, 3,12-dichloro-7-trimethylsilyl-, and 3,12-di-tert- butylpentahelicene. 3,12-Dichloropentahelicene undergoes a Suzuki-Miyaura coupling with aryl boronic acids (or ester) under palladium catalysis to afford 3,12-diarylpentahelicenes.