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Polyhemiaminal (PHA) polymers are a new class of thermosetting polymers that have recently gained attention owing to their high mechanical strength and excellent recycling behavior. However, low thermal stability is a common issue in PHA polymers due to the thermally labile crosslinked knots. Herein, crosslinked PHA polymer composites were synthesized by reacting formaldehyde with a precursor solution of 4,4ʹ-oxydianiline (ODA) and cyclodextrins (CDs) (α-, β-, and γ-). The material obtained under optimal conditions (ODA:CD molar ratio of 1:0.5, 37% aqueous solution of formaldehyde (formalin)) exhibited good film formability and high thermal stability with two characteristic decomposition phenomena and a high char yield. The early decomposition of CDs and char formation led to high thermal stability. Time-resolved NMR analysis was conducted to study hemiaminal bond formation via a condensation reaction between ODA and formaldehyde. Furthermore, PHA matrix formation was confirmed by the dissolution of the deposited CD layer in a solution of N-methyl-2-pyrrolidinone containing 8–9 wt.% LiBr at 80 °C and FTIR analysis. Based on the elemental analysis results, PHA network formation was confirmed by considering a single unit of the PHA network with CD composition, including the solvent and water.

The self-assembling gold nanoparticle (GNP)-supported l -proline derivative, which was readily synthesized in four steps from 4-hydroxy- l -proline and chloroauric acid, was used for enamine-based aldol reactions. The modified Brust-Schiffrin (BS) synthesis was favored over the ligand exchange reaction in order to develop a new and simple synthetic pathway for nanoparticle-supported catalyst. Use of immobilized organocatalyst on nanoscale solid carrier led to excellent selectivities (up to 94:6 dr and 94% ee) in asymmetric reactions of ketones and benzaldehydes. GNPs operate under pseudo-homogeneous conditions which are easily recycled and reused at least five times without significant loss of weight, activity, diastereo- and enantioselectivities.

An autoclave-free, gas–liquid–solid multiphase hydrogenation of carbon–carbon unsaturated bonds using hydrogen micro and nanobubbles (MNBs) is developed. The process allows the liquid phase of the reaction mixture to maintain a high concentration of hydrogen gas.

The synthesis and antitumor activity evaluation of new branched phospha sugars, especially deoxybromophospha sugar derivatives or bromophospholanes of 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DBMPP: 3) and 2,3,4-tribromo-3-methyl-1- phenylphospholane 1-oxide (TBMPP: 4), against various types of leukemia cell lines as well as the results of the mechanistic studies for characterizing and developing the novel multiple type molecular targeted antitumor agents are reported in this paper. DBMPP and TBMPP were prepared from 1-phenyl-3-methyl-2-phospholene 1-oxide (1). The isomer mixture of phospha sugars prepared were evaluated as novel antitumor agents by MTT in vitro method. DBMPP and TBMPP were characterized by flow cytometry and Western blot analysis and were revealed to be potential antitumor agents against leukemia cell lines of K562 (one type of leukemia cell lines of CML) and U937 (one type of leukemia cell lines of AML) as well as against the various types of leukemia cell lines and al...

The self-assembling gold nanoparticle (GNP)-supported l -proline derivative, which was readily synthesized in four steps from 4-hydroxy- l -proline and chloroauric acid, was used for enamine-based aldol reactions. The modified Brust-Schiffrin (BS) synthesis was favored over the ligand exchange reaction in order to develop a new and simple synthetic pathway for nanoparticle-supported catalyst. Use of immobilized organocatalyst on nanoscale solid carrier led to excellent selectivities (up to 94:6 dr and 94% ee) in asymmetric reactions of ketones and benzaldehydes. GNPs operate under pseudo-homogeneous conditions which are easily recycled and reused at least five times without significant loss of weight, activity, diastereo- and enantioselectivities.

Starting materials of phosphasugars, 1-phenyl-2-phospholene 1-oxides, were prepared from dienes and phenylphosphonous dichloride (dichlorophenylphosphine). Several substituted novel phosphasugars (3- or 4-halo-substituted)-1-phenyl-2-phospholene 1-oxides as well as 1-phenyl-2-phospholane 1-oxides were prepared from 2-phospholenes. The synthesized compounds were evaluated for their antitumor activities against the leukemia cell lines (U937 and K562) by in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. 2,3,4-Tribromo-3-methyl-1-phenylphospholane 1-oxide showed superior antitumor activity against U937 and K562 cell lines in a comparative evaluation with Glivec. The analysis by flow cytometry implied that 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide induced apoptosis to leukemia cell lines.

Fluorogenic aromatic aldehydes bearing arylethynyl groups were developed. They were used for monitoring the reaction progress of organocatalytic aldol reactions in DMSO through an increase in the fluorescence intensity based on the formation of the florescent aldol product. The ratios of the fluorescence intensities of the aldols to the aldehydes were more than 300. These results suggest that the fluorescence assay system using the aldehyde is useful for the rapid identification of superior aldol catalysts and reaction conditions.

A recently developed method enabled us to simultaneously characterize and quantitate glycosidically bound volatiles (GBVs) at picomole levels using liquid chromatography–mass spectrometry (LC-MS). On the basis of the analytical data it is possible to screen tea varieties most suitable for black tea processing, in which higher concentrations of primeverosides accumulate. The primeverosides decreased at the rolling step in black tea processing, whereas the glucopyranosides did not change much. The total contents of GBVs gradually increased at the withering steps and then remarkably increased after the fixing step at 230 °C, during oolong tea processing. The presence of 6′-O-malonyl ester type β-d-glucopyranosides in the tea samples suggested a contribution to the increment in glucopyranosides during oolong tea processing. The method was also used to analyze GBVs and their derivatives to understand their possible role in the metabolic pathway of tea.

Substitution on the nitrogen atom, where necessary by high-pressure SNAr reactions, of aza-18-crown-6 ethers linked to heterocyclic aromatics has extended the number of potential host compounds for Ag+. The complexation of Ag+ by the new compounds has been evaluated by liquid membrane ion transport and ion extraction experiments. The nature of the binding sites of these new host compounds for Ag+ has been assessed, in DMF/D2O (4/1), by 13C nmr titration experiments with AgClO4.

This study is focused on the synthesis and characterization of hydroxy-apo-10'-carotenal/quantum dot (QD) conjugates aiming at the in vivo visualization of β-ionone, a carotenoid-derived volatile compound known for its important contribution to the flavor and aroma of many fruits, vegetables, and plants. The synthesis of nanoparticles bound to plant volatile precursors was achieved via coupling reaction of the QD to C27-aldehyde which was prepared from α-ionone via 12 steps in 2.4% overall yield. The formation of the QD-conjugate was confirmed by measuring its fluorescence spectrum to observe the occurrence of fluorescence resonance energy transfer.

The use of hydrogen micro- and nanobubbles results in significant improvement of the efficiency of atmospheric pressure multiphase hydrogenations of unsaturated Carbon-carbon bonds.

Cyclooctyne underwent 1,3-dipolar cycloaddition with pyridinium bis(methoxy-carbonyl)methylides to afford the corresponding indolizines (8-methoxycarbonyl-7-azatricyclo[7.6.0.02-7]pentadeca-1,3,5,8-tetraenes) in good to moderate yields. Some molecular orbital considerations are also described on this reaction compared with the results on the reaction of pyridinium dicyanomethylides with cyclooctyne.

A new type of dendritic molecules, Gd–DTPA derivatives, which work as a functionalized ligand coordinating gadolinium(III) ion at the center of their frameworks with different terminal moieties on the molecular surfaces, was readily synthesized with high yield. The structures were established by 1H, 13C NMR, and mass spectral studies. In vitro studies showed them to have enhanced r1 value in albumin medium and good potentiality as MRI contrast agent.

Inclusion phenomena of the solvents such as hexane, benzene, and dichloromethane in either the crystals or glassy states of the armed-1,4,8,12-tetrazacyclopentadecanes were observed, whereas only few inclusion was found in the armed 1,4,8,11- tetraazacyclotetradecanes. As further examples of undesigned inclusion hosts, the 1:2 adduct, obtained by Diels-Alder reaction of [2.2]paracyclophane with 4-phenyl-1,2,4-triazoline-3,5-dione, along with the 1:2 adducts fiom 5-cyano- 1,4-diphenylpyridazino[4.5-a]- indolizines and dimethyl acetylenedicarboxylate (DMAD) are described.

The novel formation of anhydro -3-hydroxy-2,4-diphenyl-6-arylpyrylium hydroxide in the reaction of 3-aroylaziridines with diphenylcyclopropenones and their 1,3-dipolar cycloaddition reactions with diphenylcyclopropenone, N-phenylmaleimide, dimethyl fumarate, and dimethyl maleate were described.

Supramolecular chemistry is the study of the structure and functions of the supramolecules that result from binding substrates to molecular receptors [1a]. In this field, many chemists have been challenging either to reproduce highly sophisticated reactions occuring in living bodies, or to construct intelligent molecular systems with refined functions. This review describes representative examples of applications of high pressure to supramolecular chemistry, including the results of our efforts to construct certain supramolecules at high pressures.

The high-pressure SNAr reaction was first applied to the synthesis of new functionalized diaza-crown ethers, which are directly connected to various heteroaromatic substituents as cation binding sites. The yields of the reaction were moderate to excellent (51% to quantitative). In a CH2Cl2 liquid membrane cation-transport experiment, diaza-crown ethers having 2′-thiazoyl-, 2′-benzoxazoyl-, 2′-pyrazinyl-, and 6′-pyridazinyl groups exhibited almost perfect Ag + ion selectivity. Cation extraction and 13C-NMR titration experiments revealed that attachment of heteroaromatics to the diaza-crown ring, if in the proper position, provides excellent Ag+ ion specificity. Since the binding and transport selectivity of these crown ethers were higher than those of the known crowns, the high-pressure technique proved a useful method for synthesis odf a new type of specific crown ethers. Single crystals of the complexes of diaza-crown ethers with silver trifluoromethanesulfonate (AgO3SCF3): AgTf and the correspo...

Reactions of 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizines with dimethyl acetylenedicarboxylate afforded the 1:2 adducts regioselectively and, unexpectedly, in a Michael fashion rather than in a 1,3-dipolar manner. The structure of the products was established by X-ray crystallography. Regiospecific formation of the observed product 3 can be explained by the higher nucleophilicity of the nitrogen at the 2 position than at the 3 position of the 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizine 1 owing to the contribution of a resonance structure 5 to the hybrid. This favors two successive Michael additions to two equivalents of dimethyl acetylenedicarboxylate affording the observed 1:2 adducts 3.

Functionalized diaza-18-crown ethers and thioethers were prepared by high pressure SNAr reactions (0.8 GPa, 100°C) of 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane and the related thio analogue with heteroaromatic halides.

Title compounds were prepared through high pressure S N Ar reactions (0.8 GPa, 100 ° C) of homopiperazine with five- and six-membered heteroatomic halides, the yields being good to excellent when the halides are activated by electronic effects

Consecutive SNAr-dealkylation reactions of chlorodiazines such as 2-chloropyrimidine and 3, 6-dichloropyridazine with tertiary amines took place in a highly selective fashion.

Reactions of indolizine-3-carbonitriles with dimethyl acetylenedicarboxylate (DMAD), in the presence of Pd–C, gave the corresponding [2.2.3]cyclazines in low to moderate yields, whereas, in the absence of Pd–C, the same reactions afforded the 1 : 2 molar products. The X-ray analysis of one of the 1 : 2 adducts established that the structure was dimethyl 2-cyano-3-styrylpyrrole-1,4-dicarboxylate. A possible mechanism is presented.

The cheletropic reaction of dichlorophosphines to tricyclo[5.3.1.04,9]undeca-2,5-diene, followed by hydrolysis with water gave 6-substituted-6-oxo-6-phosphapentacyclo[6.3.1.02,4.03,7.05,10]dodecanes whose structures were established by an X-ray crystallography.

The novel formation of anhydro -3-hydroxy-2,4-diphenyl-6-arylpyrylium hydroxide in the reaction of 3-aroylaziridines with diphenylcyclopropenones and their 1,3-dipolar cycloaddition reactions with diphenylcyclopropenone, N-phenylmaleimide, dimethyl fumarate, and dimethyl maleate were described.

A new series of lariat ethers have been prepared by a high pressure SNAr reaction, in which various heteroaromatics are directly connected to the nitrogens of 12-, 15- and 18-membered aza-crown ethers. Liquid membrane transport studies demonstrated that lariat ethers having thiazole, oxazole, pyrazine and pyridazine rings on their sidearms exhibited excellent Ag+ ion selectivity. 13C NMR binding experiments revealed that these lariat ethers selectively formed encapsulated Ag+ complexes in a different fashion from that of double armed crown ethers. Cooperative action between the heteroaromatic sidearm and the aza-crown ring afforded unique cation recognition.

Cyclooctyne underwent 1,3-dipolar cycloaddition with pyridinium bis(methoxy-carbonyl)methylides to afford the corresponding indolizines (8-methoxycarbonyl-7-azatricyclo[7.6.0.02-7]pentadeca-1,3,5,8-tetraenes) in good to moderate yields. Some molecular orbital considerations are also described on this reaction compared with the results on the reaction of pyridinium dicyanomethylides with cyclooctyne.

Binuclear silver (I) complexes of double armed diaza-crown ethers, 7,16-bis(2′-thiazoyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane and 7,13-bis(2′-thiazoyl)-1,4,10-trioxa-7,13-diazacyclopentadecane were prepared. In these complexes, two Ag+ cations were cooperatively coordinated by thiazole-functionalized side arm and parent diaza-crown ring, and their Ag···Ag′ separations (2.790 and 2.969 A) were either shorter (≈0.1 A) or slightly longer (≈0.08 A) than the intermetallic distance (2.889 A), respectively.

Consecutive SNAr-dealkylation reactions of chlorodiazines such as 2-chloropyrimidine and 3, 6-dichloropyridazine with tertiary amines took place in a highly selective fashion.

A new type of dendritic molecules Gd-DTPA-XDA-D1-Glc(OH), which work as a functionalized ligand coordinating gadolinium(III) ion at the center of their frameworks with two glucose moieties on the molecular surfaces, were readily synthesized with high yield. The structures were established by IR, 1 H, 13 C NMR, and mass spectral studies. Its bio-distribution patterns were evaluated on rats.

Consecutive SNAr-dealkylation reactions of heteroaromatic chlorides such as 2-chloro-5-trifluoromethylpyridine and 2-chlorobenzothiazole with tertiary amines took place under high pressure in a highly selective fashion; some synthetic potential of the title reaction was exemplified.

Hiroko Hasegawa, Mitsuji Yamashita,* Reiko Makita, Mayumi Yamaoka, Michio Fujie, Satoki Nakamura, Tatsuo Oshikawa, Junko Yamashita, Manabu Yamada, Mitsuru Kondo, Kazutaka Hirakawa, Mitsuo Toda, Yasuo Takehara, Kazunori Ohnishi, Haruhiko Sugimura, Sophie Laurent, and Robert N. Muller 1 Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561, Japan 2 Faculty of Medicine, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan 3 Department of Chemistry and Biochemistry, Numazu National College of Technology, Numazu 410-8501, Japan 4 Faculty of Medicine, University of Mons, Mons, Hainaut, Belgium

Substitution on the nitrogen atom, where necessary by high-pressure SNAr reactions, of aza-18-crown-6 ethers linked to heterocyclic aromatics has extended the number of potential host compounds for Ag+. The complexation of Ag+ by the new compounds has been evaluated by liquid membrane ion transport and ion extraction experiments. The nature of the binding sites of these new host compounds for Ag+ has been assessed, in DMF/D2O (4/1), by 13C nmr titration experiments with AgClO4.

Cycloaddition reactions of 6-cyanobenz[a]indolizines with activated alkynes such as dimethyl acetylenedicarboxylate, diacetylacetylene, methyl propiolate, methyl trimethylsilylpropiolate, methyl phenylpropiolate, and 4-phenyl-3-butyn-2-one were investigated.

A novel P-cage type of the title compounds were discussed in terms of X-Ray analyses and molecular orbital calculations. In solid state, trans-4-phenyl-4-phosphatetracyclo[3.3.0 2,8 .0 3,6 ]octane 4-oxide (trans-5) is much more strained and asymmetric, whereas cis-6-phenyl-6-phosphapentacyclo[6.3,1.0 2,4 .0 3,7 .0 5,10 ]dodecane 6-oxides (cis-4) is less strained and highly symmetric. Molecular mechanics, semi-empirical, ab initio, and DFT calculations were used to estimate the relative energy of cis-4, trans-4, cis-5, and trans-5.