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The parent compound of azuleno[1,2-a]acenaphthylene (8) was synthesized, and its 1H NMR spectrum suggests no bond alternation in the azulene moiety. The cycloaddition of 8 with dimethyl acetylenedicarboxylate gave an acenaphthyleno[1,2-d]heptalene derivative.

Smooth radical-initiated addition of CCl 4 and CCl 3 Br to 3-[(1S)-ketopinyl]-2-oxazolone gives a 1: 1 mixture of readily separable (4S, 5R)- and (4R, 5S)-4-halogeno-5-trichloromethyl-2-oxazolidinone derivatives, which serve for facile preparation of polychlorothreonines including 4,4-dichloro-2-amino-3-hydroxybutyric acid, known as antimicrobial armentomycin analog

Chloro- and phenyl-ketene react with 2-amino-1-azaazulene 1 to give 4,4a-dihydro-1,4a-diazacyclopent[a]azulen-4-one derivatives 2a and 2b as cycloadducts. With 2-alkylamino-1-azaazulenes 4 chloroketene reacts to give anhydro-3-hydroxy-1,3a-diazacyclopent[a]azulenium hydroxide derivatives 5, whereas phenylketene gives 1-alkyl-4-benzyl-4-hydroxy-1,2,3,4-tetrahydro-1,10-diazabenz[a]azulen-2-ones 6, 2-alkylamino-3-phenylacetyl-1-azaazulenes 7 and 1-alkyl-4-benzyl-1,2-dihydro-1,10-diazabenz[a]azulen-2-ones 8. The structures of compounds 5a, 6a and 8a are deduced by X-ray structural analysis. These reactions are interpreted in the terms of the hard-soft-acid-base principle.

A new model of MnSiF6.6H2O is presented which reproduces the `weak' h0l reflections not explained with the `anti­phase domain' model by Chevrier [Acta Cryst. (1991), B47, 224–228]. Good agreement for the `weak' reflections was obtained by assuming a sort of submicroscopic twinning. The average distances are Mn—O 2.15, Si—F 1.69 and O⋯F 2.78 A.

Treatment of substituted isotellurazoles or their Te-oxides with acetylenic dienophiles efficiently afforded polysubstituted pyridine derivatives through a pathway involving hetero-Diels–Alder reaction of isotellurazoles and the subsequent tellurium extrusion from the intermediary cycloadducts.

Electron-poor chiral diphosphine ligands, MeO-F28-BIPHEP (1a) and MeO-F12-BIPHEP (1b), were synthesized for controlling a transition-metal catalyst electronically. The 1b-ligated Rh catalyst showed excellent catalytic activity with high % ee for asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated carbonyls at 20 °C. The strong π-acceptor ability of 1b induces transmetalation of arylboronic acid to catalyst precursor [RhCl(1b)]2 directly in the first step of the catalytic cycle.

The reaction of cyclopropylmethylstannane 1 with α-iodocarbonyl compounds 2 in the presence of either InBr3 or InCl3 gave the C−C coupling products 3. Various types of iodocarbonyl compounds such as esters, amides, and ketones were applied to this system to afford the corresponding cyclopropylethyl-substituted carbonyls 3. Transmetalation between cyclopropylmethylstannane and indium halides afforded butenylindium dihalide and dibutenylindium halide, as confirmed by NMR spectroscopy. The reactivity of dibutenylindium halide was greater than that of monobutenyl species. The active species, dibutenylindium halide, was stabilized by complexation using DPPE, and its structure was analyzed using X-ray crystallography. The solid state of the complex shows a linear structure with a core (−Cl−In−Cl–In–P−C−C−P−In−)n with five-coordinated indium centers. The reaction between 1 and 2, mediated by indium halides, proceeded in a radical manner. The in situ-generated alkylindium species and a small amount of oxygen, whi...

Synthetic polymers, typically prepared by addition polymerization or stepwise polymerization, are used constantly in our daily lives. In recent years, polymer scientists have focused on more environmentally friendly synthetic methods such as mild reaction conditions and biodegradable condensation polymers, including polyesters and polyamides. However, challenges remain in finding greener methods for the synthesis of polymers. Although reactions carried out in water are more environmentally friendly than those in organic solvents, aqueous media can lead to the hydrolysis of condensation polymers. Furthermore, bulk polymerizations are difficult to control. In biological systems, enzymes synthesize most polymers (proteins, DNAs, RNAs, and polysaccharides) in aqueous environments or in condensed phases (membranes). Most enzymes, such as DNA polymerases, RNA polymerases, and ribosomes, form doughnutlike shapes, which encircle the growing polymer chain. As biopolymers form, the active sites and the substrate-co...

Methylenecyclopropanes carrying a hydroxymethyl group at the ring underwent stereoselective allylindation with allylindium sesquiiodide to afford the allylated products, in which the allyl group was delivered at the external sp 2 carbon via cyclopropylindium intermediates. The reaction of ethyl 2-cyclopropylideneacetate and triallylindium afforded the 1,4-adduct along with dimeric products.

Synthetic methodologies aiming at the creation of new phosphorus-centered functional groups are reported, as well as applications to the field of nucleotide chemistry. Thus, difluorophosphonothioate-based, ionic reagents 3b and 3d are shown to allow the stereocontrolled and efficient synthesis of phosphonodifluoromethyl analogues of nucleoside-3'-phosphates. An alternate, radical approach describes the use of hypophosphorous acid to stereoselectively link two furanosyl units in positions 3 and 5, and to provide an access to alpha,alpha-difluoro-H-phosphinates. These intermediates are shown to be precursors to the corresponding fluorinated phosphonic acids, phosphonothioic acids and variously substituted phosphinates.

We developed new intravenous sedative-hypnotic compounds with the isoindolin-1-one skeleton focusing on the water-soluble property and in vivo safety. We synthesized approximately 170 derivatives and evaluated their hypnotic effects by intravenous administration of the compounds to mice. A series of the 2-phenyl-3-[2-(4-methyl-1-piperazinyl)-2-oxoethyl]isoindolin-1-one analogs, 3(-), 5(-), 27(-), and 47(-) [JM-1232(-)], showed potent sedative-hypnotic activity with good water solubility and a wide safety margin. The hypnotic doses (HD50s) of these 4 compounds when administered to mice were 2.35, 1.90, 2.17, and 3.12 mg/kg, respectively, and the lethal doses (LD50s) were 88.67, 64.69, >120, and >120 mg/kg, respectively. The therapeutic indexes (LD50/HD50) were 37.73, 34.05, >55.30, and >38.46, respectively. Among these compound, 47(-) [JM-1232(-)] is being considered as the most potential candidate for clinical trials in humans.

We newly designed and synthesized a 2 ′-deoxy type trans-3′,4′-bridged nucleic acid (trans-3′,4′-BNA) analogues bearing a 4,7-dioxabicyclo[4.3.0]nonane structure. The synthesis of the trans-3′,4′-BNA was carried out successfully from thymidine over 21 steps. The structure of trans-3′,4′-BNA was confirmed by x-ray crystallographic analysis, indicating that the furanose ring has a typical S-type conformation with C3′-exo puckering.

Reaction of 2-(1-chloro-2,2-dimethylpropyl)-1-methyl-1 H -imidazole with an excess of N , N -dimethylamine at room temperature gave an abnormal adduct, trans -4,5-bis(dimethylamino)-1-methyl-2,2-dimethylpropyl-2-imidazoline, which was derived from a serial, double nucleophilic addition into the imidazole nucleus in 74% yield together with a normal S N product, 1-methyl-2-(1-dimethylamino-2,2-dimethylpropyl)-1 H -imidazole in 15% yield. The former was easily converted to 1-methyl-5-(dimethylamino)-2-(2,2-dimethylpropyl)-1 H -imidazole by only reflux in toluene in 90% yield. The scope, mechanism and limitation of these reactions are discussed.

We review our research on the exotic behaviors in the filled skutterudite compounds RETr4Pn12 based on the transport and specific-heat measurements. Special emphasis are put on the unusual temperature versus magnetic-field phase diagrams of PrFe4P12, PrOs4Sb12, CeRu4Sb12 and CeOs4Sb12.

2-(1-Chloro-2,2-dimethylpropyl)-1-methyl-1 H -imidazole hydrochloride ( 2a ·HCl) was treated with an excess of N,N -dimethylamine at room temperature to give an abnormal addition product, 4,5-bis( N,N -dimethylamino)-1-methyl-2-(2,2-dimethylpropyl)-2-imidazoline ( 4a ), in 74.2% yield together with a normal S N 2 product, 2-(1- N,N -dimethylamino-2,2-dimethylpropyl)-1-methyl-1 H -imidazole ( 3a ), in 15.0% yield. The former might be evolved from a serial double nucleophilic addition of the secondary amine molecules to the imidazole nucleus, which has been generally considered as an electron-excessive and stable aromatic ring.

Cyano diethyl phosphate derivatives of aromatic carbonyl compounds and α,β-unsaturated ketones were successively dephosphorylated by reduction with lithium in liquid ammonia followed by treatment with isoprene or alkyl halides to give β,γ-unsaturated nitriles or α-alkyl-β,γ-unsaturated nitriles in moderate to good yields.