Helical Phenanthrenes, Part 5. Synthesis of Pentahelicene-7,8-dione via Intramolecular Benzoin Condensation

Modler‐Spreitzer, Anja; Fritsch, Rainer; Mannschreck, Albrecht

doi:10.1135/cccc20000555

Cited by 14 publications

(4 citation statements)

References 12 publications

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“…37 Partly saturated 7,8-dihydroxy-7,8-dihydro- [5]helicenes were prepared from an intramolecular benzoin-type condensation followed by oxidation in air to provide [5]helicene-7,8-dione. 38 Otherwise, a pinacol-type coupling of an enantiomerically pure binaphthyl dialdehyde using a reductive coupling with SmI 2 in THF at 0 1C afforded the enantiopure trans diol. 39 This diol was further used as a precursor monomer for synthesizing polymers with interesting chiroptical properties.…”

Section: Helicenes As Chiral Ligands or As Additives In Asymmetric Ca...mentioning

confidence: 99%

One hundred years of helicene chemistry. Part 3: applications and properties of carbohelicenes

2013

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Carbohelicenes are a class of fascinating chiral helical molecules which have a rich history in chemistry. Over a period of almost 100 years, chemists have developed many methods to prepare them in a racemic or in a non-racemic form. They also possess a series of interesting chiral, physical, electronic and optical properties. However, their utilization in chemistry or chemistry-related fields has rarely appeared in a detailed and comprehensive review. It is the purpose of this review to collect fundamental applications and functions involving carbohelicenes in various disciplines such as in materials science, in nanoscience, in biological chemistry and in supramolecular chemistry. From the numerous synthetic methodologies reported up to now, carbohelicenes and their derivatives can be tailor-made for a better involvement in several subfields. Among those domains are: nanosciences, chemosensing, liquid crystals, molecular switches, polymers, foldamers, supramolecular materials, molecular recognition, conductive and opto-electronic materials, nonlinear optics, chirality studies and asymmetric synthesis. Helicene chemistry is now at a developmental stage, where sufficient application data are now collected and are extremely useful. They provide many more ideas for setting up the basis for future innovative applications.

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Section: Helicenes As Chiral Ligands or As Additives In Asymmetric Ca...mentioning

confidence: 99%

One hundred years of helicene chemistry. Part 3: applications and properties of carbohelicenes

2013

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“…147 In another work, a pinacol coupling followed by oxidation with air afforded racemic [5]helicene-7,8-dione. 148 Based on a previous work for making phenanthrenes, 149 1,1 0 -bis(biphenylenyl)-2,2 0 -dicarboxaldehyde can be cyclized into a dibenzocyclobutene helicene by heating with hydrazine in acetic acid (Scheme 35). 150 The X-ray crystallographic data allowed for the structural determination of benzocyclobutenebased helicenes, but their preparations were not disclosed.…”

Section: Carbonyl or Pinacol Couplingsmentioning

confidence: 99%

One hundred years of helicene chemistry. Part 1: non-stereoselective syntheses of carbohelicenes

2013

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Carbohelicenes belong to a class of fascinating, chiral, and helicoidal molecules, which have a rich history in chemistry since the very beginning of the 20th century. A renewed interest in polyaromatic chemistry and new synthetic challenges toward the search for innovative physical, biological, chemical and opto-electronic properties have brought high motivation in this field of studies. Theoretical insights gained from polyaromatic, chiral, conjugated and distorted π-systems are also responsible for this development. Several synthetic avenues were originally reported for making lower helicenes, but for many years, photochemical synthesis has remained a major method for producing small amount of helicenes. High-dilution conditions is still a limiting factor in their synthesis. The fulgurous impact of organometallic chemistry, novel synthetic methods, and recent catalytic systems has promoted the development of helicene chemistry, toward a library of tailor-made and highly functionalized helicene molecules. Helicene chemistry is being considered as an expanding and modern field, leading to several applications in supramolecular chemistry, in nanosciences, in chemical-biology, in polymers and materials science. This first part of a series of three reviews on carbohelicenes will be devoted to a comprehensive report on non-stereoselective reactions and methods for producing helicenes, along with their functionalization.

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“…In contrast, oxygen gas could be employed for oxidation of hydroquinone to orthoquinone. [72][73][74][75] In this proposed redox system using gas energy, main side product is environmentally friendly and removable water, and this system could be reversible without purification. In addition, these technologies possibly apply to photoluminesence materials switching by gas energy or gas sensor for detection of hydrogen or/and oxygen by monitoring of fluorescence.…”

Section: Carbon(sp 3 )-Hydrogen Bond Activation Using Sapd(0)mentioning

confidence: 99%

Development of Metal Nanoparticle Catalysis toward Drug Discovery

Arisawa

2019

Chem. Pharm. Bull.

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Transition-metal nanoparticles (NPs) catalysts supported on solid material represent one of the most important subjects in organic synthesis due to their reliable carbon-carbon or carbon-heteroatom bondforming cross-coupling reactions. Therefore methodologically and conceptually novel immobilization methods for nonprecious transition-metal NPs are currently required for the development of organic, inorganic, green, materials, and medicinal chemistry. We discovered a self-assembled Au-supported Pd NPs catalyst (SAPd(0)) and applied it as a catalyst to Suzuki-Miyaura coupling, Buchwald-Hartwig reaction, Carbon(sp 2 and sp 3 )-Hydrogen bond functionalization, double carbonylation, removal of the allyl protecting groups of allyl esters, and redox switching. SAPd(0) comprises approximately 10 layers of self-assembled Pd(0) NPs, whose size is less than 5 nm on the surface of a sulfur-modified Au. The Pd NPs are wrapped in a sulfated p-xylene polymer matrix. We thought that the self-assembled Au-supported Pd NPs could be made by in situ metal NP and nanospace simultaneous organization (PSSO). This methodology involves 4 kinds of simultaneous procedures: i) reduction of a higher valence metal salt, ii) growth of metal NPs with appropriate size, iii) growth of a matrix with appropriate pores, and iv) wrapping of the metal NPs by matrix nanopores. This methodology is different from previously reported metal NPs-immobilizing methods, which use solid supports with preformed pores or coordination sites. We also applied the in situ PSSO method to prepare various immobilized transition-metal NPs, including base metals. For example, the in situ PSSO method can be applicable to easily prepare Ni, Ru, and Fe NPs with good recyclability and low metal leaching for use in organic synthesis. . His current research interest is in organic chemistry toward the development of medicinal chemistry. 735 Chem. Pharm. Bull. indicate that the sulfur on Au was reduced and had chemically bonded with Pd during Pd adsorption. In Pd 2p core-level photoemission spectra, the peaks from A appear close to the metallic Pd peak. These results suggest that, in the case of A, Pd(dba) 2 molecules were changed to zerovalent molecules or metallic Pd, as summarized in Fig. 4.Single crystal Au(111)/mica is not versatile. Eventually, instead of Au(111)/mica, we used Au foil and mesh to prepare B and C according to the Pd-adsorption procedure for A. When A, B, or C was subjected to the Suzuki-Miyaura coupling of 1a and 2a, the yields of the product 3a for runs 1 to 10 were excellent to quantitative in all cases, as shown in Table 1, entries 1-3. Entry 4 indicates that Material D, which was prepared from Au(mesh) with Pd(OAc) 2 as a Pd-source, was also highly active for the Suzuki-Miyaura coupling. These results show that the Pd materials A, B, C, and D are highly reactive and recyclable in this reaction.Next, we measured the amount of Pd on the Pd materials B-D using inductively coupled plasma mass spectrometry (ICP-MS) analysis. These analyses showed that in ...

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Helical Phenanthrenes, Part 5. Synthesis of Pentahelicene-7,8-dione via Intramolecular Benzoin Condensation

Cited by 14 publications

References 12 publications

One hundred years of helicene chemistry. Part 3: applications and properties of carbohelicenes

One hundred years of helicene chemistry. Part 3: applications and properties of carbohelicenes

One hundred years of helicene chemistry. Part 1: non-stereoselective syntheses of carbohelicenes

Development of Metal Nanoparticle Catalysis toward Drug Discovery

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