The site-specific reaction with high efficiency and specificity to DNA or RNA has become of great interests, as such modification may have possibility to induce point mutation of a genetic code. The cross-linking reagents within complementary duplexes and triplexes are one of the tools for site-specific modification by forming covalently bond. However, the existing alkylating agents still need further improvement for application in either in vitro or in vivo study. Previously, we have designed a new cross-linking motif, 2-amino-6-vinylpurine(1), toward cytosine by expecting a proximity effect within the complex resembling a natural G-C pair. In this paper, we wish to describe the development of the novel cross-linking reagents based on the structure of 1.

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The studies on transition metal-catalyzed addition reactions of carboxylic acids, alcohols, sulfonamides, and 1,3-diketones onto olefins toward the development of olefin hydration using transition metal catalysts were described. Both intramolecular cyclizations and intermolecular additions successfully proceeded to give the corresponding adducts under mild condition. For example, 2-allylphenol was treated in the presence of 1 mol% of (Cp^*RuCl₂)₂/4AgOTf in benzene at reflux to afford 2,3-dihydrobenzofuran in 95% yield. Ru-xantphos catalysts showed high catalytic activities on the addition of 2-phenylbenzoic acid, 2-phenylethanol, and tosylamide with 4-allylanisole to afford the corresponding addition products in 95%, 78%, and 78% yields, respectively.

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G-quadruplex (G4) is known to exist in telomeres at the ends of chromosomes, as well as in promoter regions of some oncogenes. These G4s form inherent topology, depending upon the presence of monovalent cations or the precise DNA sequence, and have characteristic biological activities. Since G4 structures have various biological functions and are expected to be a promising chemotherapeutic target, discovery of new G4 structures in genes and their ligands is of great importance. Herein, macrocyclic polyoxazole compounds based upon telomestatin, which is known as the most potent G4 stabilizing reagent, as novel G4 ligands were developed. First, macrocyclic hexa- and hepta-oxazoles namely 6OTD- and 7OTD-type G4 ligands of L2H2-6OTD, L2G2-6OTD and L1H1-7OTD were synthesized. These are selective for the telomeric oligonucleotide and strongly stabilize it in the anti-parallel G4. These compounds also showed potent telomerase-inhibitory activity. Next, fluorescence-labeled 7OTD of L1BOD-7OTD as a fluorescent G4 ligand was developed. L1BOD-7OTD selectively interacts with some G4 forming DNA by inducing and stabilizing G4 structure and can detect them as green fluorescence.

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Recently a variety of supra-molecular architectures have been successfully reported based on the strong non-covalent interactions of conjugated molecules, and their feasibility for practical electric materials has been investigated vigorously. The most important parameter determining the performance of electronic devices based on the conjugated supra-molecular architectures is the mobility of charge carriers, however the non-covalent architectures exhibit extremely wide variety of the stacking structures of the component molecules, leading to the several orders of magnitude difference in the value of mobility. The non-covalent interactions to promote supra-molecular architectures are intrinsically anisotropic, thus the value along each axis of a structure gives important insights into not only highly conducting pathways in the materials but also design strategies of the architectures for the optimized electric properties. Conventional techniques of mobility measurements, however, have not been suitable to reveal the anisotropic conductivity because of the difficulty of the electrode fabrication onto the architectures along a variety of axes. The non-contact measurement technique of electric conductivity using a microwave resonant cavity (TRMC) system has been developed, and successfully applied to estimate the value of mobility along each axis of solid supra-molecular architectures. In the present paper, we report the anisotropic nature of electric conduction in several supra-molecular architectures, as well as the direct observation of space-resolved nm-scaled mobility in the bulk solids and interfaces of conjugated molecular materials.

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Molecular iodine and hydrogen iodide are known to promote cationic species by addition to multiple bonds. The cationic species can form C-C, C-O, and C-N bonds. The development of new reactions using iodine and hydrogen iodide is playing an important role in synthetic organic chemistry. Herein we report our investigation of the carbon-carbon bond formation of conjugated compounds with iodine and hydrogen (poly)iodide using activation of the multiple bonds. Various cyclic compounds such as naphthalenes, iodobenzenes, quinolines, and dihydroquinolines were formed from aryldienes, dienynes, and enamines under thermal and photochemical conditions. We also found a unique cyclization reaction including a 1,2-sulfonyl migration using hydrogen polyiodide. The reactions specifically proceeded by the characteristic nature of the iodine element and the oxidative and reductive properties of iodine and hydrogen iodide, which were also used efficiently to yield various compounds in combination with the sulfur moiety attached to reaction materials.

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Annonaceous acetogenins are a large family of natural polyketides. So far, more than 430 related compounds have been isolated. These compounds exhibit a number of interesting biological activities including cytotoxic, antitumor, pesticidal, anti-infective properties. From a view point of mechanism of action, they are among the most potent of the known inhibitors of complex I (NADH-ubiquinone oxidoreductase) in mitochondrial electron transfer system. We report here the asymmetric synthesis of mono-tetrahydrofuran (mono-THF) acetogenins, non-tetrahydrofuran acetogenins, and tetrahydropyran acetogenins. We also wish to report structure-activity relationship (SAR) study of the inhibitory action with bovine heart mitochondrial complex I.

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Aromatic amine compounds are widely used in various fields, especially for electrical devices because of their excellent electric properties. In this short review, the syntheses of macrocyclic compounds based on aromatic amines via Buchwald-Hartwig C-N coupling reaction are described. The structure as well as ring size of arylamine macrocycles can be precisely tuned for potential applications such as high spin material and inclusion complex.

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We introduce applications of Direct Analysis in Real Time (DART) ion source, used in open-air at ground potential under ambient conditions, coupled with time-of-flight or quadrupole mass spectrometer.
DART was developed in 2005 as a new type of atmospheric pressure ion source. One of the most interesting features of DART is that researchers can access the place of ionizing point directly. It means we can observe real-time spectra of a sample at ground potential under ambient condition. In this paper, we will introduce the principles and features of DART ion source and some applications of DART mass spectrometry.

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