Showing papers in "Journal of Synthetic Organic Chemistry Japan in 1985"
TL;DR: The synthesis of indolizine derivatives and their related compounds using ketene dithioacetals is described in this paper, where the 1, 5-dipolar cyclization is used.
Abstract: The synthesis of indolizine derivatives and their related compounds using ketene dithioacetals is described. This review is concerned with following five items : 1) the 1, 5-dipolar cyclization ; 2) the reaction of picolinium salts with ketene dithioacetals ; 3) the reaction of 2-pyridyl ketene dithioacetals with α-halocarbonyl compounds ; 4) the reaction of pyridinium or isoquinolinium ketene dithioacetals ; 5) the reaction of N-imines or S-imine with ketene dithioacetals.
30 citations
TL;DR: Synthesis of pseudo-hexopyranoses (2, 3, 4, 5- tetrahydroxy-1-cyclohexanemethanols) and their derivatives are reviewed in this paper.
Abstract: Synthesis of pseudo- hexopyranoses (2, 3, 4, 5- tetrahydroxy-1-cyclohexanemethanols) and their derivatives are reviewed. In addition, synthetic studies on naturally occurring antibiotics validamycins and α-amylase inhibitors, amylostatins, adiposins, etc., which are considered to be composed of the pseudo-sugar components, are described.
18 citations
TL;DR: In this article, the designing method of optical characteristics which are important factors for the recording media for optical disk memory and also the recent trend of developing dye materials are described, which can be utilized as monolayer structure have been found.
Abstract: In optical disk memory system, recording medium is an important element. Organic dyes which were originally used as heat-mode recording media, have also been applied to the optical memory systems.In order to improve the recording characteristics, multilayer structure consisting of dyes and metals have been developed. Recently, the dyes which can be utilized as monolayer structure have been found.In this paper, the designing method of optical characteristics which are important factors for the recording media for optical disk memory and also the recent trend of developing dye materials are described.
17 citations
TL;DR: Recently, mass spectrometers have made great progress in the analytical field of biological molecules as mentioned in this paper, and the progress has mainly achieved with the development of new soft ionization techniques, such as plasma desorption, laser desorptions, molecular secondary ion mass spectria, and fast atom bombardment mass spectra.
Abstract: During the past several years, mass spectrometry has made great progress in the analytical field of biological molecules. The progress has been mainly achieved with the development of new soft ionization techniques, such as plasma desorption, laser desorption, molecular secondary ion mass spectrometry, and fast atom bombardment mass spectrometry, and with the development of a big mass spectrometer. It has been demonstrated that polar nonvolatile big bioorganic molecules can be ionized without dissociation by soft ionization methods, which are called desorption ionization. The soft ionization methods and recent applications are overviewed. Newly developed thermospray ionization seems to be obtaining a reputation as a suitable ionization method for LC/MS and several applications have been achieved more recently. The application of tandem mass spectrometry (MS/MS) to structure analysis or mixture analysis of bioorganic samples has started recently, while it was widely used as a method for analyzing the ion structure of small molecules. These combination techniques of using a mass spectrometer with a liquid chromatograph or another mass spectrometer are promising methods for mixture analysis and they are also reviewed here.
16 citations
TL;DR: In this paper, the synthesis of brassinolide, dolicholide and other brassinosteroids is reviewed with 80 references and the structure-activity relationship among these and related steroids is briefly discussed.
Abstract: Synthetic chemistry of the plant growth-promoting steroids is reviewed with 80 references. Various syntheses of brassinolide, dolicholide, homodolicholide and other brassinosteroids are analyzed. The structure-activity relationship among these and related steroids is briefly discussed.
14 citations
TL;DR: In this paper, the structural dependence of the tautomerism between cycloheptatriene derivatives and their norcaradiene tautomers dates back to the proposal of the n-Caradiene structure for Buchner's ester.
Abstract: Interest in the structural dependence of the tautomerism between cycloheptatriene derivatives and their norcaradiene tautomers dates back to the proposal of the norcaradiene structure for “Buchner's ester”. Today, the tautomerism is recognized as a typical example of electrocyclic reactions. Very recently, the spectroscopic detection of the elusive parent norcaradiene (C7H8) has been reported. In the meantime, various factors have been found to affect the equilibrium between the cycloheptatriene and the norcaradiene form. The stabilization of the norcaradiene form by a π-acceptor group on C (7) is well recognized, both experimentally and theoretically, but there still remains the possibility that a π-donor group might also stabilize the norcaradiene form. Recently, steric factors have been shown to shift the equilibrium to the norcaradiene side. So far, thirteen systems have been subjected to structural analysis by X-ray, microwave, or electron-diffraction method ; however, the prediction of the structure - norcaradiene or cycloheptatriene-in crystal appears difficult for the equilibrating systems in solution. As reactions of interest the endoperoxide formation from cycloheptatriene-norcaradiene systems and singlet oxygen, stereochemistry of the Berson-Willcott rearrangement, and solvolytic reactions are reviewed.
13 citations
TL;DR: In this article, the characteristics in the reactions of allylsilanes, especially not only enhanced reactivities towards various electrophiles due to σ-π conjugation but also regio-, stereo-, and chemoselectivities, are surveyed.
Abstract: Allylsilanes can provide synthetic strategies which are not achieved with other allylic metal reagents such as the Grignard, lithium and transition metal reagents. In this review article, the characteristics in the reactions of allylsilanes, especially not only enhanced reactivities towards various electrophiles due to σ-π conjugation but also regio-, stereo-, and chemoselectivities, are surveyed. Moreover, a variety of allylsilanes that have been synthesized and utilized as versatile synthetic equivalents are summarized.
12 citations
TL;DR: In this paper, the design, synthesis and biological activity of fluorine-modified vitamin D3 analogs are reviewed, on the basis of the metabolism of vitamins and the characteristic features of fluorines and fluorinated compounds.
Abstract: Studies on fluorine-modified vitamin D3 analogs : the design, synthesis and biological activity are reviewed. On the basis of the metabolism of vitamin D3 and the characteristic features of fluorine and fluorinated compounds, fluorine-modified vitamin D3 analogs were designed, synthesized and their biological activity was investigated to clarify the physiological significance of the metabolic hydroxylation of vitamin D3.
12 citations
TL;DR: In this article, a number of bioactive lignans and neolignans formed by the oxidative dimerization of various C6-C3 units are regio-and stereo-selectively synthesized using electrochemical method, in which anodic oxidation of the corresponding phenols as a key-step is carried out under various conditions.
Abstract: From a biogenetic point of view, a number of bioactive lignans and neolignans formed by the oxidative dimerization of various C6-C3 units are regio- and stereo-selectively synthesized using electrochemical method, in which anodic oxidation of the corresponding phenols as a key-step is carried out under various conditions. Particularly, a simple method leading to the formation of bicyclo [3. 2. 1] octanones is demonstrated.
11 citations
TL;DR: In this article, the synthesis of biologically interesting α-amino acids and heterocycles using α-isocyanoacetic acid derivatives as an anionic amino acid synthon is discussed.
Abstract: This review deals with the synthetic utilization of the isonitrile compounds ; in particular, the article focuses on the reaction of isonitrile- stabilized carban ions with an array of electrophiles. Emphasis has made on the syntheses of biologically interesting α-amino acids and heterocycles using α-isocyanoacetic acid derivatives as an “anionic amino acid synthon”.
11 citations
TL;DR: In this paper, the methods with experimental simplicity for the preparation of various alkyl (aryl) pyrimidines are reviewed and some of these are utilizable for the construction of carbon functional groups on pyrimidine rings.
Abstract: In the first half of the present paper, the methods with experimental simplicity for the preparation of various alkyl (aryl) pyrimidines are reviewed. In the second half, the reactions of alkylpyrimididines are described in view of synthetic chemistry. Some of these are utilizable for the construction of carbon functional groups on pyrimidine rings.
TL;DR: In this article, the 1, 3-cycloadditions via azomethine ylides derived from trimethylsilylmethylamine derivatives have been developed, leading to syntheses of useful heterocycles and naturally occurring compounds.
Abstract: The cycloaddition containing a desilylation process is one of the recently progressive area in the chemistry of organosilicon compounds. Especially, the 1, 3- cycloadditions via azomethine ylides derived from trimethylsilylmethylamine derivatives have been developed. In this article authors explain these 1, 3-cycloadditions via azomethine ylides, the thiocarbonyl ylide or trimethylenemethane-Pd complex and 1, 4-cycloaddition, leading to syntheses of useful heterocycles and naturally occurring compounds.
TL;DR: In this paper, a series of effective catalysts, chiral Schiff base-copper complexes, was prepared starting with an optically active α-amino acid to achieve more than 90 % e.g.
Abstract: Reaction of alkyl diazoacetate with an olefin catalyzed by a chiral copper complex gives an optically active alkyl cyclopropanecarboxylate. This chiral copper carbenoid reaction was successfully applied to the synthesis of industrially valuable cyclopropanecarboxylic acids : (+) -trans-chrysanthemic acid, (+) -cis-permethrinic acid and (+) -2, 2-dimethylcyclopropanecarboxylic acid. A series of effective catalysts, chiral Schiff base-copper complexes, was prepared starting with an optically active α-amino acid to achieve more than 90 % e.e. of the products. The chirality of the products was correlated with that of the catalyst on the basis of metallacyclobutane intermediates.
TL;DR: In this article, the authors considered the negative oxidation potential of photoreduced polyoxoanions and showed that polyoxometalates constitute an interesting family of potential sensitizer and relay species because of their variety of compositions and structure.
Abstract: Photoexcitation of the oxygen to metal charge-transfer band for alkylammonium polyoxometalates of Mo and W allows the transfer of a hydrogen-bonded proton from alkylammonium to a bridging oxygen atom at an octahedral site of the polyoxoanion and the subsequent redox reaction with water to yield reduced polyoxoanion and OH. Photoreduced polyoxoanions which exhibit oxidation potentials more negative than the reduction potential of water, lead to hydrogen generation as a result of the reduction of proton coupled with oxidation to original polyoxoanions. The significance of the highly negative oxidation potential for the photoreduced polyoxoanions can be considered in connection with the photocatalytic evolution of hydrogen from a great variety of organic molecules and their net oxidation. The polyoxometalates constitute an interesting family of potential sensitizer and relay species because of their variety of compositions and structure.
TL;DR: The chemistry of β-metallo ketones (or β-metal substituted ketones) has been reviewed in this article, but their chemistry is almost undeveloped compared with rich chemistry of their α-counter part.
Abstract: The chemistry of β-metallo ketones (or β-metal substituted ketones) has been reviewed. Though attractive and promissing, their chemistry is almost undeveloped compared with rich chemistry of their α-counter part, i. e., α-metal substituted ketones or metal enolates. This may be due to lack in general method for generation of β-metal substituted ketones. The recent approach consisting of desilylative ring cleavage of siloxycyclopropanes with metal salts has been proven successful and has opened new entry to a variety of β-metal substituted ketones. Nonconventional methods for the bond formation at β to carbonyls have been developed with the aid of β-metal substituted ketones.
TL;DR: In this paper, a variety of organic halides including aryl and alkenyl halides are catalytically converted into α-keto amides in the presence of secondary amines and palladium catalyst.
Abstract: A variety of organic halides including aryl and alkenyl halides are catalytically converted into α-keto amides in the presence of secondary amines and palladium catalyst. The scope and mechanism of the reaction are described in detail.
TL;DR: In this article, a-anions of nitroalkanes can be used as equivalents of alkyl anions, and new synthetic reactions are devised on the basis of the denitrohydrogenation with Bu3SnH.
Abstract: The nitro groups in tertiary or secondary nitro compounds are replaced by hydrogen or deuterium on treatment with tributyltin hydride or deuteride, respectively. This discovery opens a new area in organic synthesis, as a-anions of nitroalkanes can be used as equivalents of alkyl anions. Thus, following new synthetic reactions are devised on the basis of the denitrohydrogenation with Bu3SnH. (1) Conjugate addition of alkyl groups via Michael addition of nitroalkanes followed by denitration. (2) Synthesis of ketones via denitration of α-nitro ketones. (3) Synthesis of alcohols via denitration of β-nitro alcohols. (4) Regioselective deuteration. (5) New substitution reactions via radical substitution and denitration. (6) Regiocontrolled Diels-Alder reactions (7) Radical cyclization of aliphatic nitro compounds. (8) Synthesis of olefins.
TL;DR: In this article, a review of the recent developments of triphase catalysis is presented, in which applications of ion exchange resins to organic synthesis as reagents and catalysts are described in connection with polymeric phase transfer catalysts.
Abstract: Recent developments of triphase catalysis are reviewed. First, applications of ion-exchange resins to organic synthesis as reagents and catalysts are described in connection with polymeric phase transfer catalysts. Subsequently, polymeric phase transfer catalysts are classified into three typical groups, namely, onium salts type, crown ethers and cryptands type, and cosolvents type. Their specific features in triphase catalysis are demonstrated. Activity-determining factors and mechanistic aspects of triphase catalysis are also discussed.
TL;DR: The construction of orb-web, the chemical composition of secretions and the adhesive materials, the toxin of spider, the courtship and ferromon, the thermal properties of spider's drag line, the change in color of drag line and the DSC curve shows that the spider's thread should be at least stable up to 200°C.
Abstract: The paper describes the following items ; (a) the construction of orb-web, (b) the chemical composition of secretions and the adhesive materials, (c) the toxin of spider, (d) the courtship and ferromon, (e) the thermal properties of spider's drag line, (f) the change in color of drag line. For example, the toxin of spider contains spermine whose existence is detected in human semen. The DSC curve between room temperature and 600°C shows that the spider's thread should be at least stable up to 200°C. The color of drag line changes from white to yellow with changing seasons from summer to autumn. The fact suggests a possibility that the color of spider's thread protects the spider from foreign invaders.
TL;DR: Group 6 transition metal catalysts are especially effective to sterically hindered acetylenes for which Ziegler catalysts do not work as mentioned in this paper, and polymers with very high molecular weights (mot. wt. 105-106) were obtained from sterically rather hindered (e.g., HC≡C-t-Bu, CH3C≡ C-n-Pr,CH3C=CPh, ClC-≡CSi (CH3) 3).
Abstract: Group 6 transition metal catalysts (MoCl5, WCl6, MoCl5-Ph4Sn, WCl6-Ph4Sn, Mo (CO) 6-CCl4-hν, W (CO) 6-CCl4-hν etc) polymerized not only monosubstituted acetylenes (e. g., HC≡C-t-Bu) but also disubstituted acetylenes (e. g., CH3≡C_nPr, ClC≡CPh). Group 5 transition metal catalysts (NbCl5, TaCl5 etc), which selectively cyclotrimerize monosubstituted acetylenes, polymerized disubstituted acetylenes (e. g., CH3C≡CPh, CH3C≡CSi (CH3) 3). Thus these catalysts are especially effective to sterically hindered acetylenes for which Ziegler catalysts do not work. The structure and reactivity of monomers, polymer structure, and polymerization mechanism have been discussed. Interestingly, polymers with very high molecular weights (mot. wt. 105-106) were obtained from sterically rather hindered acetylenes (e. g., HC≡C-t-Bu, CH3C≡C-n-Pr, CH3C≡CPh, ClC≡CPh, CH3C≡CSi (CH3) 3). These polymers are generally white (or light yellow), soluble, amorphous, air-stable, electrically insulating, non-paramagnetic solids ; all these properties give a striking contrast to those of polyacetylene.
TL;DR: In this article, the preparation of a new polyphosphate reagent, trimethylsilyl polyphophosphate (polyphosphoric acid trimethyl silyl ester) (PPSE), and its use in organic synthesis are described.
Abstract: The preparation of a new polyphosphate reagent, trimethylsilyl polyphosphate (polyphosphoric acid trimethylsilyl ester) (PPSE), and its use in organic synthesis are described. PPSE is essentially aprotic and soluble in organic solvents and activates oxygen functions under mild conditions for preparative transformations. Some synthetically useful reactions promoted by PPSE are exemplified.
TL;DR: In this article, a review of homogeneous aerobic oxidation explored after 1980 is presented in five sections corresponding to the substrates as follows : (i) alkenes comprising of epoxidation, carbonylation, cycloaddition of dioxygen, and allylic oxygenation, (ii) arenes including oxygenation of aromatic nucleus and oxidative cleavage of catechols, (iii) oxidation of ketones, nitriles, and nitro compounds, (iv) oxidating of alkanes, and (v) oxidationof alcohols, am
Abstract: This article reviews recent results on homogeneous aerobic oxidation explored after 1980. The review is ordered in five sections corresponding to the substrates as follows : (i) oxidation of alkenes comprising of epoxidation, carbonylation, cycloaddition of dioxygen, and allylic oxygenation, (ii) oxidation of arenes including oxygenation of aromatic nucleus and oxidative cleavage of catechols, (iii) oxidation of ketones, nitriles, and nitro compounds, (iv) oxygenation of alkanes, and (v) oxidation of alcohols, amines, and divalent sulfur compounds.
TL;DR: In this article, a review describes recent highly stereo-controlled reactions of chiral aldehydes, which are classfied into Cram, anti-Cram, chelation and dipolar models.
Abstract: One of the major ongoing objectives in synthetic organic chemistry today has been the discovery and development of highly stereoselective carbon-carbon bond forming reaction. Since Cram proposed the general rules of the diastereotopic face selection of chiral aldehyde, stereoselective aldol and aldol addition reactions have been widely used in organic synthesis. Particularly during the past half decade, a number of stereo-controlled synthetic methods were devised and used as the key reactions for construction of the complex molecules. This review describes recent highly stereo-controlled reactions of chiral aldehydes, which are classfied into Cram, Anti-Cram, chelation and dipolar models. The first part presents fundamental concepts of aldol and aldol addition reactions. In the second part is discussed the reaction stereochemistry of chiral aldehydes involving α-alkoxy, α-alkyl and other aldehydes, and in the final part a double stereo-differentiation and a mutual kinetic resolution are outlined.
TL;DR: The potentiality of electroorganic chemistry in organic synthesis is briefly surveyed by exemplifying following three categories: organic synthesis using anodic oxidation of amides or carbamates as the key step, reactions using mediators, and generation of bases under the conditions of electroreduction as discussed by the authors.
Abstract: The potentiality of electroorganic chemistry in organic synthesis is briefly surveyed by exemplifying following three categories.(1) Organic synthesis using anodic oxidation of amides or carbamates as the key step.(2) Reactions using mediators.(3) Generation of bases under the conditions of electroreduction, and their utilization in organic synthesis.The potentiality of commercialization of electroorganic methods is also briefly discussed.
TL;DR: In this article, a review deals with the recent advances in the synthesis of pyrrolizidine alkaloids, especially in the syntheses of PRL bases (necines) and macrocyclic bislactonic PRL alkaloids.
Abstract: Pyrrolizidine alkaloids have attracted much interest as synthetic targets, and various efficient synthetic routes leading to the pyrrolizidine skeleton have been developed. This review deals with the recent advances in the syntheses of pyrrolizidine alkaloids, especially in the syntheses of pyrrolizidine bases (necines) and macrocyclic bislactonic pyrrolizidine alkaloids.
TL;DR: This review describes the stabilization by steric protection using bulky group and the physical and chemical properties of the highly reactive low-coordination organophosphorus species such as diphosphenes and the related compounds, phosphaalkenes, imino-phosphines, and phosphacumulenes.
Abstract: Very recently, the chemistry of the double bonds between the elements more than third period has received extensive attention. This review describes the stabilization by steric protection using bulky group and the physical and chemical properties of the highly reactive low-coordination organophosphorus species such as diphosphenes and the related compounds, phosphaalkenes, imino-phosphines, and phosphacumulenes.
TL;DR: In this paper, the synthesis, structures, and reactions (reductions, 1, 4-additions, hydrolyses, Diels-Alder additions, reactions with aromatic compounds, Grignard reagents, amines, sulfonylchloramides, phosphorus compounds, active methylene compounds, enamines, diazoalkanes, etc.) of the title compounds are reviewed.
Abstract: Syntheses, structures, and reactions (reductions, 1, 4-additions, hydrolyses, Diels-Alder additions, reactions with aromatic compounds, Grignard reagents, amines, sulfonylchloramides, phosphorus compounds, active methylene compounds, enamines, diazoalkanes, etc.) of the title compounds are reviewed. Their applications to color photography are also described.