有機合成化学協会誌
Online ISSN : 1883-6526
Print ISSN : 0037-9980
ISSN-L : 0037-9980
79 巻, 4 号
選択された号の論文の10件中1~10を表示しています
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総説および総合論文
  • 石垣 侑祐
    2021 年 79 巻 4 号 p. 290-299
    発行日: 2021/04/01
    公開日: 2021/04/07
    ジャーナル 認証あり

    The carbon-carbon covalent bond is one of the most basic concept in organic chemistry. Bond length, bond angle, and torsion angle among carbon atoms are nearly constant on the basis of the bond order and hybrid orbitals. On the other hand, highly strained hydrocarbons such as sterically-congested and/or curved polycyclic aromatic hydrocarbons have attracted much attention with regard to their characteristic features. Regarding the C-C single bond, whose standard length is 1.54 Å, several attempts have been made to elongate the C-C single bond to gain new insight into the chemical bond and understand what happens at the limits of a bond. In contrast to the standard C=C double bond with planarity, the overcrowded ethylenes (OCEs) with bulky substituents can adopt anti-folded, syn-folded and/or twisted forms due to the steric hindrance around the central C=C double bond, and thus many OCEs exhibit photo- and thermochromic behavior upon exposure to external stimuli. Herein, we focus on redox-active hydrocarbons with two dibenzocycloheptatriene units, where unprecedented flexible C-C bonds based on extremely elongated C-C single bonds and control of HOMO levels were demonstrated. Thus, these highly strained hydrocarbons could be promising candidates for the development of functional materials.

  • 柘植 顕彦
    2021 年 79 巻 4 号 p. 300-310
    発行日: 2021/04/01
    公開日: 2021/04/07
    ジャーナル 認証あり

    In the past two decades, the low-molecular-weight gelators have gained much attention due to promising technological applications in various fields as well as their fundamental scientific interests. Large structural diversity has been proposed to meet the requirements of the organogelators capable of gelling organic solvents. On the other hand there have been reported the gelators categorized as an ambidextrous gelator which can simultaneously act as both an organogelator and a hydrogelator. These ambidextrous gelators could be unique materials because of immobilizing organic solvents and water at the same time. The bottom-up strategy to build gelators based on molecular design is attractive from the viewpoint of inspiring development of the next generation of functional soft matter. In this review our recent progresses of organogelators consisting of various functional groups and two-component gelling systems are described. In addition, a development of aromatic ambidextrous gelators in terms of designing the parts of the molecular structure is also mentioned.

  • 松尾 貴史
    2021 年 79 巻 4 号 p. 311-321
    発行日: 2021/04/01
    公開日: 2021/04/07
    ジャーナル 認証あり

    Hoveyda-Grubbs-type complexes with a ruthenium center coordinated by an N-heterocyclic carbene (NHC) and a 2-alkoxybenzylidene ligands have gained increased applicative importance as catalysts for olefin metathesis because the complexes have suitable reactivities and stabilities in a wide range of reaction media. Furthermore, this type of catalysts has also been applied for biochemical research projects including the construction of artificial biocatalysts and the regulation of in-cell bioreactions because the ruthenium-olefin interaction, a driving force of olefin metathesis mediated by Hoveyda-Grubbs-type complexes, provides the specificity among functional groups in biomolecules. In this context, we have investigated the structural modification of Hoveyda-Grubbs-type complexes aiming at the application of the complexes to biomolecules. In parallel, we have also studied the mechanism of olefin metathesis in aqueous media. In this article, we firstly describe the construction of an artificial metalloenzyme with olefin metathesis activity using α-chymotrypsin. The artificial metalloenzyme displayed the substrate specificity with the protein surface charge state. Next, we demonstrate the importance of chloride anion in solutions to attain efficient olefin metathesis reactions in aqueous media and the reactivity control of Hoveyda-Grubbs-type complexes through second-coordination sphere effect. Finally, we introduce the ruthenium complex transfer reaction between Hoveyda-Grubbs-type complexes and biomolecules (peptides and proteins) through the ruthenium-olefin specific interaction. The reaction potentially serves a new type of chemical modification strategy toward biomolecules.

  • 浅井 禎吾
    2021 年 79 巻 4 号 p. 322-332
    発行日: 2021/04/01
    公開日: 2021/04/07
    ジャーナル 認証あり

    A synthetic biology method based on heterologous biosynthesis coupled with genome mining is a promising approach to translate tremendous amount of genomic information to richly diverse natural products in the post-genomic era. In addition, this approach increases the opportunities to rationally access not only novel skeletal natural products but also new structural analogues of bioactive natural products. For example, the reconstruction of cryptic biosynthetic pathways in heterologous hosts may discover novel natural products, while pathways that are related to those of bioactive natural products lead to access to their natural analogues. In addition, pathway redesign for combinatorial biosynthesis in heterologous hosts enables access to natural product congeners that are not programmed in nature. Here, we demonstrate the advantage of the synthetic biology method to explore biological activity-related chemical space through the comprehensive heterologous biosynthesis of fungal decalin-containing diterpenoid pyrones (DDPs), which are potential sources of pharmaceutically beneficial natural products.

  • 中村 斐有, 安井 孝介, Phil S. Baran
    2021 年 79 巻 4 号 p. 333-343
    発行日: 2021/04/01
    公開日: 2021/04/07
    ジャーナル 認証あり

    Teleocidine B family was isolated in1960 by Sakai group and was shown to have highly potent protein kinase-C (PKC) activation, similar to that of phorbol and related natural products. In this report, we have developed a unified total synthesis of teleocidins B-1-B-4 in 11 chemical steps. The highlights of the work are 1) the Ni catalyzed electrochemical amination, 2) Cu-mediated aziridine opening followed by direct macrolactamization, and 3) the tactical combination of C-H borylation and a redox-relay chain walking (RRCW) methodology to make the carbon quaternary center.

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