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Rhodium-catalyzed intramolecular reductive aldol-type cyclization was described to give β-hydroxylactones with high diastereoselectivities. This cyclization gave syn- or anti-form β-hydroxylactones selectively by changing the solvent. Furthermore, the synthesis of a chiral necic acid lactone was also described which is a part of structural component of pyrrolizidine alkaloid monocrotaline that is used for the preparation of pulmonary hypertension pathological model in rats.

X-ray fluorescence (XRF) core scanner elemental count data are useful for high-resolution paleoceanographic studies. However, because several factors, such as changes in physical core properties, significantly affect element count intensities, the appropriate calibration of the count data is required. Besides, the existing approaches for calibration were not widely employed and require rigorous testing based on sediment variety. In this study, we analyzed high-resolution element intensity (cps) using a wet muddy marine sediment piston core that was collected from the northeast Gulf of Alaska and tested several approaches with ratio and log-ratio methods, and the reliability was evaluated by comparison with the concentrations that were measured by WD-XRF and an elemental analyzer. The results show that the lighter elements (Ti and K) exhibited a significantly weak relationship between raw counts measured by ITRAX and concentrations that were measured by the WD-XRF, indicating that some factors artificially influence ITRAX intensity data. The Cl intensity that is expressed as the water content in marine sediment increased significantly in the upper 202 cm by 42% and the top 25 cm by 73% as compared to the down-core (below 202 cm), which deviates the X-ray scattering and element-counts. The calibration of raw data through coherent/incoherent X-ray scattering ratio (CIR) and additive- and centered-log ratio reduces the offsets. The calibration by CIR performed best for Sr, Fe, Mn, Ti, Ca, K, and Br (0.56 &lt, R2 &lt, 0.91), and the correlation with concentration significantly increased for Ti and K of 100% and 56%, respectively. Therefore, the study suggests that the correction of raw counts through CIR is an effective approach for wet marine sediment when core physical properties have greater variability.

An efficient one-pot synthesis of 1,2,3-triazole-fused isoindoles from o-alkynylbenzaldehydes and trimethylsilyl azide (TMSN3) is reported. The reaction proceeds through the formation of a diazide intermediate and a subsequent intramolecular azide-alkyne cycloaddition, providing a novel access to a variety of 8-azido-8H-[1,2,3]triazolo[5,1-a]isoindoles in high yields.

The syntheses of 2,3-dihydro-4-quinolones from 2-propargylphenylcarbamates by one-pot tandem process that involves Meyer-Schuster rearrangement or arylative Meyer-Schuster rearrangement/Michael addition of carbamate nitrogen to the resulting vinyl ketones have been developed. Phenylcarbamates tethering tertiary propargyl alcohols underwent arylative Meyer-Schuster rearrangement/Friedel-Crafts alkylation to produce 2,3-dihydroindenones.

A central theme of the ongoing GEOTRACES program is to improve the understanding of processes occurring at ocean interfaces with continents, sediments, and ocean crust. In this context, we studied the distributions of Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb around the Juan de Fuca Ridge (JdFR) in total dissolvable (td), dissolved (d), and labile particulate (lp) fractions, which represent a fraction in unfiltered samples, filtered samples through an AcroPak capsule filter, and the difference between td and d, respectively. Al and Fe were dominated by lp-species, while Ni, Zn, and Cd were dominated by d-species with undetectable amounts of lp-species. Major findings in this study are as follows: (1) The continental margin (CM) provided large sources of Al, Mn, Fe, and Co from the surface to ~2000 m in depth. The supply from CM caused high surface concentrations of dMn and dCo, a subsurface (100–300 m depth) maximum of dCo, and intermediate (500–2000 m depth) maxima of lpAl and lpFe. The supply of dFe from CM was ~10 times that from the high-temperature hydrothermal activity at station BD21, which is located at ~3 km from the Middle Valley venting site and ~ 200 km from Vancouver Island. (2) DPb was maximum at the top layer of North Pacific Intermediate Water, probably owing to isopycnal transport of anthropogenic Pb via advection of subducted surface waters. Although dCo and dPb had different sources in the upper water, they showed a strong linearity below 300 m (r 2 = 0.95, n = 38), indicating concurrent scavenging. (3) A high-temperature hydrothermal plume occurred at a depth of 2300 m at BD21, accounting for maxima of dAl, dMn, dFe, lpCu, and lpPb and a minimum of dCu. (4) Strong bottom maxima of lpAl, lpMn, lpFe, lpCo, and lpPb occurred above the abyssal plain at the western foot of the JdFR, indicating resuspension of sediments. However, bottom maxima of d-species were apparent only for dAl and dCu.

Copper-catalysed arylative ring-closing reactions of 2-alkynylphenylcarbamates and 2-alkynylphenylureas with diaryliodonium salts gave C,N-double-arylated benzoxazin-2-ones and C-arylated benzoxazin-2-amines, respectively, both bearing fully substituted exocyclic olefins. On the other hand, the palladium-catalysed arylative ring-closing reaction of 2-alkynylphenylcarbamates gave C-arylated 2,3-disubstituted indoles.

We report an efficient synthetic route to 9-arylfluorenes and biaryl compounds from 1,6-diynes and aldehydes via inter- and intramolecular alkyne-carbonyl metathesis/1,6-addition/oxidative aromatization reactions. These tandem reactions are initiated by a BF3·Et2O-promoted tandem inter- and intramolecular alkyne-carbonyl metathesis of 1,6-diynes with carbonyl compounds followed by an In(OTf)3-catalyzed 1,6-addition/oxidative aromatization with iodobenzene diacetate.

A new approach to form iminoisocoumarins from readily available and stable 2-alkynylbenzamides was developed by using a tandem copper-catalyzed N-arylation and regioselective 6-endo-dig cyclization in the presence of diaryliodonium salts, a copper catalyst, and 2,6-di-tert-butylpyridine. The arylation occurred at the nitrogen atom rather than the oxygen atom of the amide group, the alkynyl carbon, or the benzene ring of the benzamide. Cyclization occurred through a preferential nucleophilic attack by the oxygen rather than the nitrogen atom of the amide group to produce iminoisocoumarin derivatives in good to moderate yields.

Primary productivity is very high in the Sea of Okhotsk, most likely because of terrigenous input from the Amur River that includes dissolved matter and suspended matter. To reveal the transport and deposition processes of the fluvial materials in the northwestern continental shelf of the Sea of Okhotsk, the Sr and Nd isotopes of the detritus in the surface sediments and suspended matter were investigated. The regional variations of the radiogenic isotopes indicate that the detritus in the continental shelf has three main sources: Amur River detritus, with a high 87 Sr/ 86 Sr ratio (0.711–0.715) and relatively low e Nd value (−7.6 to −7.3); volcanic detritus derived from the Okhotsk-Chukotka volcanic belt to the north of the Okhotsk Sea, with a low 87 Sr/ 86 Sr ratio (0.703) and high e Nd value (+7 to +8); and detritus from the sedimentary rocks north of Sakhalin Island, with a high 87 Sr/ 86 Sr ratio (0.709–0.710) and low e Nd value (−10.2 to −9.2). The results indicate that the Amur River detritus is dispersed across the northwestern continental shelf and further transported southward along the east coast of Sakhalin while flowing out of the shelf. Around the northeast coast of Sakhalin Island, the coarse-grained detritus from the north region of Sakhalin Island is distributed only in the narrow region of the shallow depth area and is not transported to the shelf slope. The Amur River detritus flowing out of the shelf is mixed with the Okhotsk-Chukotoka volcanic material transported from the northern area of the Okhotsk Sea by the Okhotsk Sea intermediate water (OSIW). The transport processes of the Amur River detritus in this area are supported by previous studies of turbidity that indicated that the dense shelf water (DSW) entrains resuspended sedimentary particles on the northwestern continental shelf and transports them to the OSIW.

An enantioselective Reformatsky reaction has been developed for the reaction of ethyl dibromofluoroacetate (1) with an imine. This method represents the first ligand-promoted imino-Reformatsky approach to use a halofluoroacetate. The use of an amino alcohol ligand allowed for the preparation of enantioenriched α-bromo-α-fluoro-β-lactams in good yields with enantioselectivities up to 96% ee. This process also provided access to β-lactam rings bearing two stereogenic centers.

Time series of biogenic sinking particle flux in the western North Pacific subpolar region over two decades (1989–2008) revealed that the biogenic CaCO3 (CC) flux has shown a significant decreasing trend of 2.7% year−1 (annual average, −0.88 ± 0.13 mg m2 day−1 year−1) along with the decreasing particulate organic carbon (POC) flux of 0.7% year−1, while the biogenic opal (OP) flux had no long-term trend. Comparing these results with the decreasing rate of satellite-derived surface CC with −0.7% year−1, we concluded that three fourths of the decreasing trend of CC flux was derived from the strengthening of CaCO3 dissolution through seawater column due to the weakening of water ventilation and the rest was from the decline of CaCO3-shelled species, indicating the enhancement of the efficiency in oceanic sequestration of atmospheric CO2 in the sea surface of this region due to the increase of OP/CC ratio.

A novel exopolysaccharide-producing bacterium, designated strain SE3T, was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase-positive and catalase-positive, and required Na+ for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile mainly consisted of C16 : 1ω7c, C16 : 0 and C18 : 1ω7c. The DNA G+C content was 46.9 mol%. 16S rRNA gene sequence analysis suggested that strain SE3T is a member of the genus Pseudoalteromonas . Strain SE3T exhibited close phylogenetic affinity to Pseudoalteromonas arabiensis JCM 17292T (99.0 % 16S rRNA gene sequence similarity), Pseudoalteromonas lipolytica LMEB 39T (98.39 %) and Pseudoalteromonas donghaensis HJ51T (97.65 %). The DNA–DNA reassociation values between strain SE3T and P. arabiensis JCM 17292T, P. lipolytica JCM 15903T and P. donghaensis LMG 24469T were 31, 26 and 44 %, respectively. Owing to the significant differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene sequences and DNA–DNA relatedness data, the new isolate merits classification as a representative of novel species, for which the name Pseudoalteromonas shioyasakiensis is proposed. The type strain is SE3T ( = JCM 18891T = NCIMB 14852T).

A highly diastereoselective cross-coupling reaction of an α-bromo-α-fluoro-β-lactam with a wide range of aryl Grignard reagents was catalyzed by Ni/bis(oxazoline) in yields of up to 98%. The product was obtained diastereoselectively as an anti-isomer. This is the first successful α-arylation of an α-fluoro-β-lactam to produce diverse α-aryl-α-fluoro-β-lactams.

An effective synthesis for syn-β-lactams was achieved using a Rh-catalyzed reductive Mannich-type reaction. A rhodium–hydride complex (Rh–H) derived from diethylzinc (Et2Zn) and a Rh catalyst was used for the 1,4-reduction of an α,β-unsaturated ester to give a Reformatsky-type reagent, which in turn, reacted with an imine to give the syn-β-lactam. Additionally, the reaction was applied to the synthesis of (±)-ezetimibe, a potent β-lactamic cholesterol absorption inhibitor.

An effective synthesis for syn-β-lactams was achieved using a Rh-catalyzed reductive Mannich-type reaction. A rhodium–hydride complex (Rh–H) derived from diethylzinc (Et2Zn) and a Rh catalyst was used for the 1,4-reduction of an α,β-unsaturated ester to give a Reformatsky-type reagent, which in turn, reacted with an imine to give the syn-β-lactam. Additionally, the reaction was applied to the synthesis of (±)-ezetimibe, a potent β-lactamic cholesterol absorption inhibitor.

A new approach to form iminoisocoumarins from readily available and stable 2-alkynylbenzamides was developed by using a tandem copper-catalyzed N-arylation and regioselective 6-endo-dig cyclization in the presence of diaryliodonium salts, a copper catalyst, and 2,6-di-tert-butylpyridine. The arylation occurred at the nitrogen atom rather than the oxygen atom of the amide group, the alkynyl carbon, or the benzene ring of the benzamide. Cyclization occurred through a preferential nucleophilic attack by the oxygen rather than the nitrogen atom of the amide group to produce iminoisocoumarin derivatives in good to moderate yields.

The chemoselective and diastereoselective synthesis of syn-α-bromo-α-fluoro-β-lactams was achieved using the diethylzinc-mediated Reformatsky-type reaction of ethyl dibromofluoroacetate with imines. The reaction led to diastereomerically pure β-lactams in good to moderate yields (up to 78% yield) with only small amounts of aziridine derivatives. Noncyclized 3-amino-2-bromo-2-fluoro carboxylic esters, usual Reformatsky adducts, were not formed. In contrast, reactions carried out under typical Reformatsky conditions using zinc metal were poorly chemoselective, leading to mixtures of β-lactams and aziridine derivatives.

In order to discuss the dry deposition fluxes of atmospheric fixed nitrogen species, observations of aerosol chemistry including nitrate (NO 3 − ) and ammonium (NH 4 + ) were conducted at two islands, Rishiri Island and Sado Island, over the Sea of Japan. Although the atmospheric concentrations of particulate NH 4 + –N showed higher values than those of particulate NO 3 − –N at both sites, the dry deposition fluxes of the particulate NO 3 − –N were estimated to be higher than those of the particulate NH 4 + –N. This was caused by the difference of particle sizes between the particulate NO 3 − and NH 4 + ; NH 4 + was almost totally contained in fine particles ( d 3 − was mainly contained in coarse particles ( d > 2.5 μm) with greater deposition velocity. Fine mode NO 3 − was strongly associated with fine mode sea-salt and mineral particles, of which higher concentrations shifted the size of particulate NO 3 − toward the fine mode range. This size shift would decrease the dry deposition flux of the fixed nitrogen species on coastal waters and accelerate atmospheric transport of them to the remote oceanic areas.

A direct conversion architecture reduces the cost and power consumption of a receiver. However, a direct conversion receiver may suffer from direct current (DC) offset, frequency offset, and IQ imbalance. This paper presents an IQ imbalance estimation scheme for orthogonal frequency division multiplexing (OFDM) direct conversion receivers. The proposed IQ imbalance estimation scheme operates in the presence of dynamic DC offset and frequency offset. The proposed scheme calculates IQ imbalance from a simple equation. It employs the knowledge of the preamble symbols of the IEEE 802.11 a/g standards, while it does not require the impulse response of the channel. Numerical results obtained through computer simulation show that the bit error rate (BER) performance for the proposed IQ imbalance estimation scheme has a degradation of about 4 dB with a large DC offset, frequency offset, and IQ imbalance.

Starting from ortho-alkynylbenzaldehydes and ortho-alkynylanilines, In(OTf)3-catalyzed synthesis of ring-condensed heteroaromatic compounds was developed via a domino intramolecular nucleophilic attack/intermolecular cycloaddition/dehydration reaction.

Total 230 Th and 228 Th vertical distributions were measured in the eastern Indian Ocean. Based on disequilibria of 234 U– 230 Th and 228 Ra– 228 Th, we estimated the particle flux from the surface to 950 m. The estimated particle flux ranged from 190±60 (150 m in the Southern Ocean) to 8.4±2.5 mg/m 2 /day (950 m in the West Australian Basin). The particle fluxes correlate well with estimates of nitrate supply by vertical mixing to the euphotic zone, suggesting local control by new production. Flux attenuation at mesopelagic depths appears to be related to biogenic carbonate and silica remineralization based on comparison to alkalinity and dissolved silicate distributions, with possible additional control by lithogenic particle inputs. The particle flux estimates obtained by combining the 234 U– 230 Th and 228 Ra– 228 Th disequilibria offer advantages over those from 228 Ra– 228 Th disequilibrium alone, in that they can account for some aspects of vertical mixing and thus are applicable to a wider range of oceanographic settings.

This study was undertaken to investigate trace metals in southeast Asian seas that have different hydrographic settings: the Philippine, the Celebes, and the Sulu seas. Results reveal characteristics of dissolved and leachable manganese, dissolved cerium, and leachable iron in the water column. Remarkable increases of Mn, Ce, and Fe exist at the bottom layer of the water column in the Celebes Sea. The Ce/Mn molar ratios in the bottom waters of the Celebes Sea are identical to those in the porewaters of the underlying sediment. Both Ce and Mn show similar geochemical cycles in these deep waters of the Celebes Sea. In the Sulu Sea's deep waters, the leachable particulate fractions are dominant for Fe and Mn. The residence time of Fe in the Sulu Sea is estimated as 12 years. This residence time estimate is very similar to the particle residence time in the water column, implying that resuspension of sediment-derived particles affects leachable Fe distributions in the Sulu Sea.

Thorium-230 concentrations were determined in the Sulu Sea, a small 5000 m deep basin surrounded by the Philippine and Malaysian Islands, and the South China Sea. The mid-water of South China Sea flows into the Sulu Sea through the Mindoro Strait (sill depth 420 m). Thorium-230 concentrations in deep waters at two stations (PA-1 in the Sulu Sea and PA-11 in the South China Sea) are considerably lower than those in the open ocean (average concentrations below sill depth: 0.49 dpm/m 3 (PA-1), 0.79 dpm/m 3 (PA-11)). The low concentration and homogeneity of 230 Th in deep water below sill depth are consistent with the trend of other semi-closed basins such as the Japan Sea. We also measured 232 Th concentration in the Sulu Sea. From these data, terrigenous 230 Th was calculated to be 19% of the measured 230 Th in the basin. The most probable explanation for the 230 Th deficit in the deep water of the Sulu Sea is an enhanced scavenging effect by the particles supplied from the seafloor. Using a simple box model, the amount of 230 Th scavenged by particles supplied from the seafloor is calculated to be 0.052 dpm/m 3 /y.

Aryl alkyl alkynes reacted with N-iodosuccinimide (NIS) and trimethylsilyl azide (TMSN3), leading to α,α-diazidoketones via the regioselective addition of IN3 to alkynes. Huisgen cyclization of α,α-diazidoketones generated bis-triazole compounds.

Aryl alkyl alkynes reacted with N-iodosuccinimide (NIS) and trimethylsilyl azide (TMSN3), leading to α,α-diazidoketones via the regioselective addition of IN3 to alkynes. Huisgen cyclization of α,α-diazidoketones generated bis-triazole compounds.

A novel exopolysaccharide-producing bacterium, designated strain 9a2T, was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase- and catalase-positive, and required NaCl for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile consisted mainly of C16 : 1ω7c, C18 : 1ω9cand C16 : 0. The DNA G+C content was 46.6 mol%. 16S rRNA gene sequence analysis suggested that strain 9a2Tis a member of the genusAlteromonas. Strain 9a2Texhibited closest phylogenetic affinity toAlteromonas macleodiiNBRC 102226T(99.3 % 16S rRNA gene sequence similarity),A. marinaSW-47T(99.3 %),A. litoreaTF-22T(99.0 %),A. australicaH17T(98.7 %),A. simiduiiBCRC 17572T(98.5 %),A. stellipolarisLMG 21861T(98.3 %) andA. hispanicaF-32T(98.2 %). The DNA–DNA reassociation values between strain 9a2TandA. macleodiiJCM 20772T,A. marinaJCM 11804T,A. litoreaJCM 12188T,A. australicaCIP 109921T,A. simiduiiJCM 13896T,A. stellipolarisLMG 21861TandA. hispanicaLMG 22958Twere below 70 %. Strain 9a2Tcontained phosphatidylethanolamine, phosphatidylglycerol and an unidentified polar lipid. Owing to differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene sequences and DNA–DNA relatedness data, the isolate merits classification as representing a novel species, for which the nameAlteromonasgracilissp. nov. is proposed. The type strain of this species is 9a2T( = JCM 30236T = NCIMB 14947T).