著者
石垣 侑祐
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.79, no.4, pp.290-299, 2021-04-01 (Released:2021-04-07)
参考文献数
35

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.
著者
谷口 剛史
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.77, no.6, pp.584-595, 2019-06-01 (Released:2019-06-11)
参考文献数
41
被引用文献数
1

The Mitsunobu reaction is widely used for transformation of hydroxy groups into various functional groups and inversion of the stereochemistry of secondary alcohols in organic synthesis. The Mitsunobu reaction, however, has some serious problems that inhibit its application of the reaction to practical synthesis on large scales. Especially, the reaction requires hazardous azo reagents such as diethyl azodicarboxylate (DEAD) and produces large amounts of undesired waste that sometimes complicate purification of the desired products. We have recently developed catalytic Mitsunobu reactions using new azo reagents recyclable by iron-catalyzed aerobic oxidation. Ethyl 2-(3,4-dichlorophenyl)hydrazinecarboxylate and ethyl 2-(4-cyanophenyl)hydrazinecarboxylate (or their azo forms) were identified as good catalysts by our systematic investigation. The modified catalytic reaction using these azo reagents was applicable to broad scope of substrates. High thermal stability of the reagents was shown by SC-DSC analysis, suggested low explosive nature of these reagents.
著者
友重 秀介
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.77, no.3, pp.264-266, 2019-03-01 (Released:2019-03-07)
参考文献数
9

Bacteria possess a cell wall based on a rigid extracellular matrix comprised of peptidoglycan (PG), which maintains their structural integrity. Although PG is a molecule that has attracted interest from various research fields, such studies have been limited by the difficulty to isolate the desired PG fragments. In order to make PG fragments available, many efforts have been made to achieve their synthesis. This review summarizes the synthetic strategies reported for the construction of PG fragments by the Fukase and Fujimoto’s group as well as the Mobashery’s group. Furthermore, applications of synthetic PG fragments in chemical biology are described.
著者
浜田 翔平
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.78, no.8, pp.813-815, 2020-08-01 (Released:2020-08-06)
参考文献数
10

DNA encoded library (DEL) has emerged as a widely utilized chemical library, possessing DNA-tag on each compound, for discovering hit compounds in drug discovery. However, synthetic methods for DEL are not fully exploited due to the difficulty in chemical transformation of DNA encoded compounds. This mini-review focuses on the recent development on organic synthesis for diversity expansion of DEL.
著者
加藤 南
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.77, no.2, pp.185-186, 2019-02-01 (Released:2019-02-08)
参考文献数
8

Two dimensional Covalent Organic Frameworks (2D COFs) are new porous materials synthesized from only organic molecules. The 2D COFs consist of light elements that can form strong covalent bonds. The properties of 2D COFs such as pore size, shape and character are easily controlled. The 2D COFs are expected to be applied for a gas storage, an electrochemical device and so on. This review summarized the characteristics and new synthetic methods of 2D COFs.
著者
山内 泰宏 星本 陽一 生越 專介
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.79, no.7, pp.632-641, 2021-07-01 (Released:2021-07-07)
参考文献数
72

Practical methods have been established for the synthesis of multifunctional N-heterocyclic carbenes (NHCs) via the introduction of substituents on either the nitrogen atom(s) or the backbone of the NHCs. However, their use has been mainly limited to acting as multidentate ligands for metal complexes. Herein, results of our recent studies on the synthesis and application of N-phosphine oxide-substituted imidazolylidenes (PoxIms) as novel type of multifunctional NHCs are discussed. PoxIms were used not only as a mono-/bi-dentate ligand for mono-/bi-metallic complexes, but also as an external stimuli-responsive Lewis base for achievement of the frustration revival strategy as well as a reagent for the direct phosphinoylation of CO2 and carbonyl compounds. These results manifest the pioneering role of PoxIms as a multifunctional multipurpose NHC.
著者
松尾 貴史
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.79, no.4, pp.311-321, 2021-04-01 (Released:2021-04-07)
参考文献数
49

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.
著者
中村 斐有 安井 孝介 Phil S. Baran
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.79, no.4, pp.333-343, 2021-04-01 (Released:2021-04-07)
参考文献数
32

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.