著者

田辺 陽 御前 智則 飯田 聖 西井 良典

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.62, no.12, pp.1249-1259, 2004-12-01 (Released:2009-11-13)

参考文献数

46

被引用文献数

5 7

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Esterification, sulfonylation, amide formation, and silylations are well recognized as frequently used reactions for organic syntheses. Recent syntheses of fine chemicals and complex natural products, however, require further rationalization of these reactions. We describe herein our recent studies in this area including related representative known methods.(i) Recent progresses of catalytic esterifications are surveyed and we introduce two efficient ammonium triflate catalysts (DPAT and PFPAT) for esterification between 1 : 1 mixture of carboxylic acids and alcohols. (ii) Conventional condensation reagents for esterifications, thioesterifications, and amide formation, are listed and we introduce efficient methods using Me2NSO2Cl/ Me2NR and p-TsCl/N-methylimidazole. (iii) As a promising method for the replacement of conventional pyridine-method, we introduce efficient pyridine-free improved methods, which utilize sterically uncrowded tertiary amines such as Me3N·HCl/Et3N and Me2N (CH2) nNMe2 as a key protocol. (iv) We introduce highly powerful, neutral, and catalytic methods for silylations of alcohols (giving enol ethers) and ketones (giving enol silyl ethers) using hydrosilanes, disilanes, and silazanes.

著者

太田 明広

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.26, no.2, pp.115-131, 1968-02-01 (Released:2009-11-13)

参考文献数

122

被引用文献数

1

著者

松本 澄

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.30, no.12, pp.1035-1042, 1972-12-01 (Released:2009-11-13)

参考文献数

51

被引用文献数

3 3

著者

廣戸 聡 忍久保 洋

出版者

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.76, no.1, pp.37-44, 2018-01-01 (Released:2018-01-16)

参考文献数

37

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Recently, π-conjugated molecules with curved-π surface have attracted considerable interest for their unique properties originating from their curved structures. However, most of them consist of only carbon and hydrogen atoms. In these situations, we have developed novel synthetic protocols for construction of distorted structures directly from 2D π-conjugated molecules under mild reaction conditions. By applying phenol and aniline oxidation methods, we have succeeded in the synthesis of highly distorted cyclophanes, π-extended heterohelicenes, and highly twisted porphyrin oligomers. Furthermore, we have succeeded in the synthesis of a nitrogen-embedded buckybowl as a novel bowl-shaped π-conjugated molecule with a pyrrolic nitrogen in its skeleton. These heteroatom containing curved-π conjugated molecules exhibit unique characteristics due to the combination of the curved structure with heteroatoms such as circularly polarized luminescence, strong C60 binding, and near IR electrochromism. We believe that the chemistry of heteroatom containing curved-π conjugated molecules would enhance the potential of three-dimensional π-conjugated molecules for molecular materials.

著者

佐々木 茂貴

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.55, no.7, pp.590-599, 1997-07-01 (Released:2009-11-16)

参考文献数

39

被引用文献数

2 2

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The triplex formation between the duplex and a single strand DNA has been shown to inhibit transcription at the specific DNA site, and expected as a new biological tool and a new therapeutic method in the so-called antigene strategy. However, native oligonucleotides can form triplexes only within the major groove of the homopurine-homopyrimidine stretch of DNA, and the triplex is destabilized either at a TA or a CG interrupting site. Despite a number of methods have been attempted to expand the limitation of triplex formation, this problem has not been generally solved. This review describes (1) molecular design to stabilize triplex at a TA or a CG interrupting site, including new recognition molecules which have been recently shown by the reviewer and coworkers to be specific toward each base pair. And (2) some method to enhance stability of triplexes with use of DNA binding molecules such as intercalators, cross-linking agents, and groove binders are also discussed.

著者

寺田 晁 田上 保博 谷口 博重

出版者

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.48, no.10, pp.866-875, 1990 (Released:2009-11-13)

参考文献数

81

被引用文献数

5 8

---

The roots of Lithospermum erythrorhizon Sieb. and Zucc., (violet root, Japanese name, Shikon) contain shikonin and its esters as purple pigments. The coloring matter of the root of Alkanna tinctoria in Europe is a mixture of the enantiomeric alkannin and its esters. The racemic compound of shikonin and alkannin was named shikalkin by R. Kuhn and H. Brockmann. From ancient times these purple pigments have been well-known as valuable materials having antiinflammatory, antibacterial, antitumor actions, and as ancient purple deys and cosmetics. Here, the history, structural determination, synthesis and pharmacology of shikonin, alkannin, and their derivatives will be reviewed.

著者

中西 香爾

出版者

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.58, no.5, pp.462-465, 2000-05-01 (Released:2009-11-13)

参考文献数

3

---

私は1963年に東京教育大学 (現筑波大学) から東北大学理学部の藤瀬新一郎教授の後任として赴任し, 幸運にも藤瀬研で手がけ始めたイチョウ成分の単離構造研究に携わることになった。この構造研究は構造決定がいわゆるルーチン化して推理小説を解くような興奮がなくなる直前になされたものであるが, 異常構造に基づく異常反応, 異常スペクトル現象が続出し, 研究者一同を大いに悩ませ, 楽しませてくれた。その上ギンコライドは血の流れ滑らかにして記憶力増進, アルツハイマー病の悪化防止に効果があるとして急激に需要が増えているイチョウエキスの有効成分の1つとしてここ数年急速に脚光を浴びてきている。イチョウは古生代 (250億年前) に出現した属の生き残りで, 一属一種しかなく, 化石の木といわれている。世界中に繁茂していたが絶滅し, わずか中国の寺院などに残っていたものが, 1800年後半に世界中に紹介され, 再び各国で見られるようになった。構造が最終的に出たのは1967年の夏であるが, 構造決定には珍しいくらいの感動の瞬間がいくつかあった 。私が行った構造研究では群を抜いて印象に残るものであり, 私にとり浪漫的な最後のクラシカル研究である。研究に携わったのは丸山雅男, 寺原昭, 中平靖弘, 板垣又丕, V.Woods (故人), 高木良子, 幅口一夫 (故人), 広田勇二, 菅原徹, 出井敏雄, 宮下正昭と私である。仙台に台風が来たおかげでイチョウが倒れ, 仙台市の許可を得て5本を伐採しその根皮100Kgから抽出, 再結晶を10数回繰り返し (液クロ以前の時代, NMRも100MHz) 10gずつのGAとGB, 20gのGCと200mgのGMを得た。ギンコライドは多形や混晶を形成する傾向が強く, ずいぶんてこずった。構造決定中に作られた50個の誘導体は今でも最低数ミリずつ小グラス管にいれられ, 立派なサンプル箱に整頓されてコロンビア大の研究室に保存されている。丸山さん以下よくこんなに整理ができたものといまさらながら感心している。

著者

石渡 明弘 伊藤 幸成

出版者

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.70, no.4, pp.382-394, 2012-04-01

被引用文献数

9

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1,2-cis Glycosidic linkages are prevalent in natural glycans. Although key factors that control stereoselectivity of glycosylation have been largely understood, stereoselective synthesis of 1,2-cis glycosides is potentially problematic. To achieve exclusive formation of desired isomer, approaches based on intramolecular aglycon delivery (IAD) are of special promise. In the last two decades, various mixed acetal linkages and a number of glycosyl donor moieties have been making much progress to develop novel IAD strategies, mainly based on formation of the acetal linkages.The methodology toward the strereoselective 1,2-cis glycosylation using naphthylmethyl (NAP) ether-mediated IAD has been developed. Namely, 2-O-NAP protected donor was cleanly converted to the mixed acetal upon oxidative activation with DDQ. Subsequent activation of thioglycosidic linkage initiated the rearrangement of an aglycon from mixed acetal moiety to give a desired 1,2-cis glycoside. Stereospecific constructions of various 1,2-cis linkages, which are not only β-mannopyranoside but also other linkages such as β-L-rhamno-, α-glucopyrano- and β-arabinofurano-sides, were achieved through NAP-IAD. This methodology was successfully applied to the synthesis of various fragments of natural glycans.

著者

長谷川 賢

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.25, no.2, pp.116-126, 1967-02-01 (Released:2011-03-01)

参考文献数

74

著者

鈴木 章

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.28, no.3, pp.288-308, 1970-03-01 (Released:2009-11-16)

参考文献数

219

被引用文献数

3 4

著者

杉浦 幸雄

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.39, no.11, pp.1097-1104, 1981-11-01 (Released:2009-11-13)

参考文献数

35

被引用文献数

1

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Cleavage of cellular DNA by bleomycin substantially contributes to the antitumor activity of this drug. Two characteristics are necessary for antineoplastic action of bleomycin. First, the bithiazole region of the antibiotic has an affinity for the guanine base of DNA. Second, the β-aminoalanine-pyrimidine-β-hydroxyhistidine portion of the drug is capable of oxygen activation by the complexation with Fe (II) ion. The role of the gulose-mannose group and unique interaction between the iron-coordination site and the DNA-binding site have been also indicated. Several spectroscopic data have clearly demonstrated that the bleomycin-Fe (II) complex forms a complex with either CO, C2H5NC, or NO. The “site specific oxygen radical”, produced from an active bleomycin-Fe (II) complex, would account for the action mechanism of selective DNA base cleavage by bleomycin. In addition, the inactivation mechanism of bleomycin hydrolase and important effect of the fifth axial amino group to iron-coordination on bleomycin activity have been discussed.

著者

黒須 三千夫 岸 義人

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.62, no.12, pp.1205-1217, 2004-12-01 (Released:2009-11-13)

参考文献数

37

被引用文献数

6 7

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The batrachotoxins are a unique class of steroidal alkaloids isolated in minute quantities from the skins of poison arrow frogs (genus Phyllobates) as well as from the skins and feathers of New Guinea birds (genus Pitohui and Iflita) and exhibit various unique structural features, including a steroid-based pentacyclic core skeleton, an intramolecular 3-hemiketal, and a seven-membered oxazapane ring. These compounds are extremely potent neurotoxins (batrachotoxin (2), LD50 in mice 2 μg/kg) that act as selective and irreversible Na+-channel activators. In this paper, we review historical background of isolations and structure determinations of batrachotoxins and our studies on the total synthesis of (-) -batrachotoxinin A (1). Strategic bond-forming events include the stereospecific epoxidation of the double bond (9→10), a new Garst-Spencer protocol to construct 3, 4-disubstituted furan (14b→17b), the stereoselective intramolecular furan Diels-Alder reaction to assemble the steroidal skeleton (20d→22d), a novel intramolecular oxy-Michael reaction to close the oxazapane ring (31→33), an organocerium addition to form the α-enone (39b→40), and the simultaneous reduction and optical resolution of the racemic ketone to provide both enantiomers of a molecule (rac-41→43, 44).

著者

小倉 克之

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.37, no.11, pp.903-913, 1979-11-01 (Released:2009-11-13)

参考文献数

36

被引用文献数

7 6

---

During our investigation to search useful derivatives of dimethyl sulfoxide, we encountered a new sulfoxide, methyl methylthiomethyl sulfoxide which was also named formaldehyde dimethyl dithioacetal S-oxide. Now, this compound is designated conveniently as “FAMSO” by abbreviating he latter name.FAMSO was first synthesized by substitution of chloromethyl methl sulfoxide with a methanethiolate anion and it was later found that this compound could be more easily produced by oxidation of formaldehyde dimethyl dithioacetal with hydrogen peroxide. To date, many papers on organic syntheses using FAMSO have been published and it has appeared to be a versatile reagent for making a variety of organic compounds such as aldehydes, cyclic or acyclic ketones, α-hydroxy aldehydes, α-amino acids, α-keto acids, and α-arylalkanoic acids.This review will disclose the details of the production of FAMSO and its utilization for organic syntheses.

著者

水口 憲哉

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.57, no.1, pp.47-52, 1999-01-01 (Released:2009-11-16)

著者

西依 隆一

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.81, no.7, pp.731-732, 2023-07-01 (Released:2023-07-06)

参考文献数

9

---

Quantum mechanical tunneling (QMT) is a quantum mechanical phenomenon that enables particles to penetrate potential energy barrier despite a lack of energy to overcome it. It has become clear that how important tunneling is for understanding the rates and selectivities of chemical reactions in the last few years. In this short review, recent examples of hydrogen tunneling reactions are described.

著者

小田木 陽 山中 正浩

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.81, no.7, pp.706-717, 2023-07-01 (Released:2023-07-06)

参考文献数

48

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Organocatalysis has become widely used since the early 2000s as a third type of catalysis in addition to the two types of catalysis, metals and enzymes, and the Nobel Prize in Chemistry was awarded in 2021 for its pioneering achievements. In organocatalytic reactions, stereoselectivity is often controlled by the cooperative action of weak interactions such as hydrogen bonding and dispersion interactions, and it is extremely difficult to elucidate the stereocontrol mechanism from experimental perspectives. On the other hand, recent advances in computational chemistry have made it possible to deeply understand transition state and clarify important roles in controlling the stereoselectivities in organocatalytic reactions. Furthermore, the findings computationally revealed can provide guidelines for the design of new reactions and catalytic structures. Herein, we describe asymmetric oxidation reactions using conformationally flexible bifunctional guanidine-bisurea organocatalysts developed by us and theoretical analysis of the transition states of these reactions. We also discuss the development of novel catalytic reactions and catalyst designs based on the obtained transition state models.

著者

高井 和彦

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.70, no.4, pp.323, 2012-04-01 (Released:2012-04-24)

著者

阿部 匠 山田 康司 西 剛秀

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.6, pp.597-607, 2020-06-01 (Released:2020-06-12)

参考文献数

80

被引用文献数

6 8

---

C3-Nucleophilic substitution of indoles has been limited because the transformation requires an umpolung of the C3 position of indoles. Among the indole derivatives, indole-2,3-epoxides could be potentially be used as C3-electrophilic reagents due to the electrophilic nature of the C2 and C3 positions. However, their use as C3 electrophilic reagents has not been possible so far due to their instability.We describe a novel and bench stable surrogate of indole-2,3-epoxide, 2-hydroxyindoline-3-triethylammonium bromide (HITAB), which was found to be a convenient reagent for formal C3-electrophilic reactions of indoles with nucleophiles. By taking advantage of the nucleophilic character of the oxygen of the 2-hydroxyindoline, interrupted retro-Claisen and interrupted Feist-Bénary reactions with 1,3-dicarbonyl compounds, one-pot formation of furodiindolines from 3-substituted indoles were achieved. Furthermore, we developed a novel cascade reaction of the indole-2,3-epoxide surrogate with γ-carbolines to access multiheterocyclic compounds containing both isotryptamines and pyrimido[1,6-a]indoles. This reaction utilizes the in situ formation of a bulky quaternary ammonium salt via ammonium exchange, which undergoes Hofmann elimination/vinylogous Mannich/retro-Mannich/cyclization cascade sequences. The synthetic potential of the ammonium salts was demonstrated by the short synthesis of cryptolepine, iheyamine A, racemocine B derivative, and neocryptolepine derivative.

著者

首藤 紘一 岡本 敏彦

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.32, no.9, pp.670-686, 1974-09-01 (Released:2009-11-13)

参考文献数

95

被引用文献数

4 5

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環境毒のうちでも発がん性物質ほど恐ろしいものはない.発がん性物質には天然起源のものに加えて, この半世紀の問の有機合成化学の進歩と共に産まれたものも少なくないし, 環境汚染の問題が日を追って重大になっていく昨今, 発がん性物質への理解を高めることは, 合成化学者にとっても, いろいろな意味で必要と思われる.また, ここ数年間の発がん物質の化学・生化学の進歩により, 有機化学的な理解が可能になり, 同時に, ますます有機化学の寄与が求められているのが現状である.本稿では, 化学物質による発がんについての近年の考え方と, 発がん物質の分類と反応性について, 化学的立場からまとめてみたい.

著者

生長 幸之助

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.81, no.4, pp.366-380, 2023-04-01 (Released:2023-04-08)

参考文献数

42