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A series of dipolar-type terphenyl derivatives 1–3 featuring an electron donor (p-NMe2C6H4 group) and acceptor (p-NO2C6H4 group) unit was synthesized and their photophysical properties were investi...

In the present paper, we report the mechanism of water and oil repellency (both static and dynamic) of methacrylate-based polymers with fluoroalkyl group side chains. Surface rearrangement has the ...

Oxidation-responsive oligonucleotides (ONs) can exhibit controlled functions by sensing dysregulated oxidation conditions in living systems. Herein, we describe a postmodification approach to const...

The ruthenium(II)-catalyzed ortho-C–H arylation of 2-aroyl-imidazoles with aryl bromides and chloride is reported. An imidazole ring functions both as a masked ester and a directing group for C–H a...

The effect of the head group on the oxidation of unsaturated phospholipids under low-level ozone was investigated. The phospholipids with head groups of glycerol and choline show different surface-...

Bis(2-pyridylcarbonyl)aminate (bpca) coordinates to a ruthenium center with three nitrogen atoms of two pyridyl and one aminate group and the biscarbonylaminate moiety ({O-C-N-C-O}−) functions as a...

The goal of this account is to detail the steps taken by our group for the development of glycosylated artificial metalloenzymes (GArMs), which we have used in our endeavors to develop examples of ...

In the past few decades, synthetic organic chemistry has been invigorated with the development of transition metal catalyzed directing group assisted regioselective C–H functionalization. Although ...

Two novel organogelators that incorporate sugar acetate segments have been identified. One contains a sugar acetate linked directly to an alkyl group, while the second includes an amide linker. We ...

Comprehensive conformational analyses of 1-alkyl-3-methylimidazolium cations ([Cnmim]+ where n = 2–6) were performed by DFT calculations with dispersion correction in the gas phase. The energy diff...

We have developed the synthesis of 1,3,6,8-tetramethoxy-2,7-diazapyrene through reductive aromatization of naphthalene diimide. The methoxy groups were readily converted to a variety of alkyl group...

Degradation of 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (1), a model compound for lignin β-O-4 linkage was examined with iron, ruthenium, rhodium and iridium complexes bearing c...

The versatility of the synthesis of sulfonated aromatic polymers using NiBr2 was investigated. The copolymerization of sulfo-dichlorobenzene protected with a neopentyl group was carried out with ch...

Dual hydrogen bonding intramolecular bridge pivoted by fluoro group for 1,2-bis(2-fluorophenyl)-3,8-dimethoxy-acenaphthenediol in solution is ascertained as simultaneous contribution of mutual fluo...

Poly(glycidyl methacrylate) (poly(GMA)) bearing pendant glycidyl groups, grafted on the surface of MgO-templated carbon (MgOC), is useful for forming strong multipoint covalent bonds with amino fun...

In-situ powder X-ray diffraction study of AlMepO-α under varied nitrogen equilibrium pressures identifies two phases np and lp with the same space group and slightly different lattice constants and...

p-Aminopyridines were oxidatively substituted at the C31-position of methyl pyropheophorbide-a, a chlorophyll-a derivative. The electron-donating p-dimethylamino groups induced silver metallation d...

Bigels consist of a relatively new group of soft materials, developed using two or more networks to achieve synergistic multifunctionalities. Covalently crosslinked bi-hydrogels from two different ...

Zinc cis-7,8-dihydroxy-pyrobacteriochlorophyll-a lacking the 7,8-dihydrogen atoms and 132-methoxycarbonyl group was prepared by chemical modification of naturally occurring chlorophyll-a as a model...

Heterogeneous catalytic reaction at low temperatures (

A Sc(OTf)3-catalyzed activation of a single C–F bond in a CF3 group is described. This reaction has two interesting features: (1) the synthesis of difluoromethylene compounds through Lewis acid-cat...

Dcdftbmd developed in our group was an efficient quantum chemical calculation code based on the divide-and-conquer density functional tight-binding (DC-DFTB) method. The bottleneck for its applicat...

The iridium-catalyzed direct C–H borylation of ring-fused (hetero)arenes afforded borylated products in a peri-selective manner, directed by a proximal hydrosilyl group. Further selective transformations of the boryl and silyl groups enabled the synthesis of various multisubstituted (hetero)arenes, such as 1,8-disubstituted naphthalenes and 3,4-diarylindole.

A previously reported odd-even effect is found to invert by substituting a phenyl with a cyclohexyl group. Crystal structures of [Ni(dmit)2]− complex salts of ω-cyclohexylalkyltrimethylammonium (Cn...

Stereoisomerism of cyclopropanes is systematically discussed by means of stereoisograms and their correlation diagrams. A cyclopropane skeleton is governed by a main RS-stereoisomeric group constru...

5,15-Bis(pentafluorophenyl)-10-nitrocorrole and its pyridinate Ga(III) complex were obtained by nitration of the corresponding meso-free corroles in moderate yields. The acidity of the central NH proton proved to be significantly increased in the freebase form, suggesting the stabilization of 2NH-corrole anionic state due to the resonance effect of the nitro group. Fluorescence quenching was observed for meso-nitrocorrole and its Ga(III) complex.

Stereoisomerism is one of the most fundamental and indispensable notions in chemistry. We have recently found that a novel form of stereoisomerism emerges in cycloarylenes, cyclic arrays of aromatic panels. Structural rigidity that is a precondition for chirality has been realized in an unconventional manner with the cyclic structures, which gives rise to unique cyclostereoisomerism affording diastereomers and enantiomers. In this account, structural chemistry of cylindrical cycloarylenes synthesized in our group will be reviewed with an emphasis on stereochemistry. The relevant studies in this new field will deepen our understanding of the fundamental structural chemistry of finite single-wall carbon nanotube molecules.

1-(Perfluoroalkylethyl-X)-4-alkoxybenzenes (X = thio for 1-m,n and X = sulfonyl for 2-m,n) were synthesized as a new class of rod-shaped organic gelators without hydrogen-bonding groups. Compounds 1-m,n and 2-m,n form gels in several polar solvents to give physical gels. The gel-sol transition temperatures of propylene carbonate gels were about 30 °C–80 °C, depending on the chemical structures of the compounds. The formed gels consist of fibrous structures.

Trp*, a novel triptycene (Trp)-based aliphatic steric protection group was synthesized, and its potential to offer kinetic stabilization by steric protection was evaluated in the context of synthes...

The regioselective silylation of the α-C(sp3)–H bond in the 2-alkyl group in 2-alkyl-1,3-azole derivatives with hydrosilanes, catalyzed by the combination of (POCOPtBu)IrHCl and NaBArF4, leading to...

In this article, the selective recognition of sugars was investigated using lectin-inspired polymer which was composed of temperature-responsive polymer with sugar-binding benzoxaborole group. This polymer bound sugar selectively and showed excellent phase-transition behaviors dependent on the sugar type, concentration, and temperature.

Imide- or amide-based π-systems, as represented by naphthalenediimides (NDIs), perylenediimides (PDIs), or diketopyrrolopyrroles (DPPs), have been extensively studied owing to their characteristic optical properties, their electronic structures, and so forth. Here, we present syntheses of NDIs, a PDI, and a DPP with ethynyl substituents, and their use as new building blocks for the synthesis of amino-functionalized electron-accepting π-conjugated systems. The reaction between the ethynyl group of the electron acceptor and an amine proceeds almost quantitatively, without a catalyst, to give a Michael-addition-type product that shows remarkable changes in its optical properties, redox properties, and dipole moment. The progress of the reaction can be visually monitored in various media. On the basis of a kinetic analysis of the amine-addition reaction, various amino-functionalized asymmetric and symmetric π-systems were obtained in a designed manner.

The reactions of phosphonates having a binaphthyloxy group with Grignard reagents gave the corresponding P-stereogenic phosphinates in good to high yields with high diastereoselectivity. In this reaction, an axis-to-center chirality transfer from a binaphthyl group to the resulting phosphorus atom took place stereospecifically. Both diastereomers with opposite configurations could be obtained by changing the combination of carbon-containing functional groups on the phosphorus atom and the Grignard reagents.

Temporary modification of a boronyl group with pyrazorylaniline allowed insertion of arylpropiolates and diphenylacetylenes into the o-C–H bond of arylboronic acids in the presence of rhodium catalysts, giving 3,3-diarylacrylates and triarylethene containing aryl groups bearing an o-boryl group stereoselectively. The boronyl group in the 3,3-diarylacrylates was converted into various functional groups, including chlorine, hydrogen, hydroxy, and aromatic groups.

Reaction of thiofenchone with acyl chlorides in the presence of AlCl3 in refluxing dichloromethane gave Wagner–Meerwein products and 2-acyloxynorbornan-1-thiols. When ZnCl2 was used as a Lewis acid, norbornan-1-thiols were obtained as major products along with Wagner–Meerwein products. The reaction might proceed through 5-membered cyclic carbocation (oxathiacarbocation) intermediates.

The synthesis and characterization of thermally stable monosubstituted thiophene 1-oxide and 1-imides stabilized by EMind (1,1,7,7-tetraethyl-3,3,5,5-tetramethyl-s-hydrindacen-4-yl) group on the 3-position are described. In addition to the molecular structures determined by X-ray crystallography, inversion barriers at the three-coordinated sulfur atoms have been determined by a coalescence method using diastereotopic C-3 and C-5 indacene carbon atoms as a 13C NMR probe.

The substituent effect at the C6-position of 1,3a,6a-triazapentalenes was elucidated. Synthesis of C6-substituted-1,3a,6a-triazapentalene was established by an epoxide-opening reaction of the 1,2,3-triazoles followed by elimination of the resulting hydroxy group. The electron-donating substituent induced a longer-wavelength shift of the fluorescence maximum and change of the fluorescence quantum yield depending on the C2-substituents. On the other hand, the electron-withdrawing group quenched the fluorescence of 1,3a,6a-triazapentalenes.

Hydrophilicity and hydrophobicity of ionic liquids are readily controlled by attaching or removing a protective group of a diol unit in their cationic part.

A novel, peripherally extended sterically demanding primary alkyl group based on the triptycene (Trp) framework, Trp*CH2, was designed and synthesized via a convenient one-pot reaction using the Friedel-Crafts alkylation of the corresponding TrpCH2 precursor. The introduction of the Trp*CH2 groups onto a Si=Si double bond allowed isolating the first stable tetraalkyldisilene that contains primary alkyl groups.

A new PS3-type tripodal tetradentate ligand, P(2-t-BuSC6H4)3 (1b), was synthesized by reaction of PCl3 with 2-t-BuS(C6H4)Li. Reaction of ligand 1b with NiCl2·6H2O resulted in the elimination of t-BuCl to afford the corresponding 5-coordinate nickel complex, [NiCl{P(2-SC6H4)(2-t-BuSC6H4)2}] 6. In addition, ligand 1b reacted with [PdCl2(PhCN)2] and [PtCl2(cod)] to give 4-coordinate square planar palladium and platinum complexes, [MCl{P(2-SC6H4)(2-t-BuSC6H4)2}] (7: M = Pd, 8: M = Pt), respectively, via the elimination of t-BuCl. Further elimination of t-BuCl from palladium complex 7 proceeded by heating of 7 in CDCl3 at 100 °C for 4 h to form dipalladium complex, [Pd2{P(2-SC6H4)2(2-t-BuSC6H4)}2] (9). The isopropyl-substituted palladium and platinum complexes, [PdCl{P(2-i-PrSC6H4)3}]Cl (3a) and [PtCl2{P(2-i-PrSC6H4)3}] (5), also underwent the elimination of i-PrCl by the thermolysis in CDCl3 at 60 °C to afford the corresponding complexes, [MCl{P(2-SC6H4)(2-i-PrSC6H4)2}] (11: M = Pd, 12: M = Pt). The structure...

Our research group demonstrated the semi-synthesis of complex-type biantennary sialyloligosaccharide-library by means of branch-specific glycosidase and several sialyltransferase reactions toward c...

A novel phenylacetylene derivative containing a pyrene group was synthesized and polymerized with various Rh complex catalysts. The obtained polymers were soluble in common organic solvents such as...

Intramolecular C–H···H–C contacts in a set of 10 molecules, being formaldehyde and thioformaldehyde disubstituted with such a heteroaryl group as 2-furanyl, 2-thiophenyl, 2-selenophenyl, 2-pyrrolyl...

Phosphangulene derivatives having various substituents on the phosphorus atom, which featured a bowl geometry and restrained bond angle, were synthesized in order to shed light on the relationship ...

For the purpose of characterizing cubane derivatives, the RS-stereoisomeric group and the corresponding stereoisograms are formulated by t...

We developed novel reaction conditions for the removal of the diphenylmethyl group, which is one of the most important protecting groups for amines. The reaction was promoted by adding one equivalent of camphorsulfonic acid in aqueous media, and no acidic solvent was required.

We newly synthesized an amino-functionalized zeolitic imidazolate framework (ZIF), [Zn{(dmamIM)n(mIM)m}2]∞ (dmamIM−: 2-[(dimethylamino)methyl]imidazolate; mIM−: 2-methylimidazolate), through a liga...

During the development of new synthetic organic reactions by the use of group 4–7 metals, we twice encountered a reproducibility problem. The key factor was trace amounts of second metal elements t...

Fluorophores with intramolecular charge-transfer (ICT) character in the excited state exhibit significant solvatochromism of their fluorescence. Here, we report an example for such compounds, a ben...

Boron, a group 13 element, has several characteristic structural and electronic features: 1) trivalent boron compounds usually adopt a trigonal planar geometry; 2) due to the presence of a vacant p...