Asymmetric Hydrogenation of 3‐Amido‐2‐arylpyridinium Salts by Triply Chloride‐Bridged Dinuclear Iridium Complexes Bearing Enantiopure Diphosphine Ligands: Synthesis of Neurokinin‐1 Receptor Antagonist Derivatives

We describe a most straightforward synthetic method for preparing neurokinin‐1 (NK1) receptor antagonist derivatives by asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts using dinuclear iridium complexes with enantiopure diphosphine ligands, affording the corresponding chiral piperidines in high cis‐diastereoselectivity (>95:5) and moderately high enantioselectivity (up to 86%). Deprotection treatments afforded the NK‐1 receptor antagonist (+)‐CP‐99,994 (83% ee). In addition, we observed unique additive effects of 10‐camphorsulfonic acid in the asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts.

     

Iridium‐Catalyzed Asymmetric Hydrogenation of Tosylamido‐Substituted Pyrazines for Constructing Chiral Tetrahydropyrazines with an Amidine Skelton

Dinuclear triply chloro‐bridged iridium(III) complexes bearing chiral diphosphine ligands catalyze the asymmetric hydrogenation of tosylamido‐substituted pyrazines to give the corresponding chiral tetrahydropyrazines with an amidine skeleton in high yield and with high enantioselectivity. Addition of N,N‐dimethylanilinium bromide enhanced the catalytic activity of the iridium complexes and also increased the enantioselectivity of the products by trapping the hydrogenated amine products with HBr from N,N‐dimethylanilinium bromide. The amidine skeleton of the products could be transformed to give chiral piperazinones and piperazines without loss of enantioselectivity.

     

Functional analysis of genes encoding putative oxidoreductases in Aspergillus oryzae, which are similar to fungal fructosyl-amino acid oxidase

We found 11 genes (FAO1-11) encoding putative oxidoreductases in the Aspergillus oryzae genome, which are similar to fungal fructosyl-amino acid oxidases. The cDNAs corresponding to the genes were cloned and expressed in Escherichia coli. rFao2 had fructosyl-amino acid oxidase activity, whereas rFao1 did not show any enzyme activity, even though the deduced amino acid sequence of Fao1 is identical to that of one of the fructosyl-amino acid oxidase isozymes from Aspergillus oryzae. rFao7 and rFao8 showed oxidase activity toward sarcosine, L-pipecolate, and L-proline. rFao10 was active toward only sarcosine, of the substrates tested. The functions of the other proteins were also predicted from a phylogenetic analysis.     

Application of microalgae hydrolysate as a fermentation medium for microbial production of 2-pyrone 4,6-dicarboxylic acid

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Synthesis of porphyrin-end-functionalized poly(p-phenylene) as a leaf-green-colored soluble semiconducting polymer: Control of π–π interactions for visible-light absorption

The synthesis of tetraphenylporphyrin (H₂TPP)-end-functionalized poly(p-phenylene) (H₂TPP-PPP) as a leaf-green-colored soluble semiconducting polymer with a well-controlled and defined polymer chain structure was achieved for the first time. Chloromethyl-end-functionalized poly(1,3-cyclohexadiene) (CM-PCHD) was prepared by the living anionic polymerization of 1,3-cyclohexadiene and the post-polymerization reaction of poly(1,3-cyclohexadienyl)lithium and chloro(chloromethyl)dimethylsilane. H₂TPP-end-functionalized PCHD (H₂TPP-PCHD) was then prepared by the addition of 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin to CM-PCHD. The dehydrogenation of H₂TPP-PCHD with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone was performed under ultrasonic irradiation, and H₂TPP-PPP was obtained as a target polymer in almost quantitative yield. The –Si(CH₃)₂–CH₂–O– bond in H₂TPP-PPP effectively inhibited the coordination of the H₂TPP end-group onto the PPP moiety, and the aggregation of H₂TPP-PPP with the accumulation of the H₂TPP end-group was formed. H₂TPP-PPP exhibited a leaf-green color and had a very broad absorption band overlapping the visible-light region, similar to chlorophyll a.     

Natural convection heat transfer from a horizontal cylinder in liquid sodium: Part 2: generalized correlation for laminar natural convection heat transfer

Rigorous numerical solution of natural convection heat transfer, from a horizontal cylinder with uniform surface heat flux or with uniform surface temperature, to liquid sodium was derived by solving the fundamental equations for laminar natural convection heat transfer without the boundary layer approximation. It was made clear that the local and average Nusselt numbers experimentally obtained and reported in part 1 of this paper were described well by the numerical solutions for uniform surface heat fluxes, but that those for uniform surface temperatures could not describe the angular distribution of the local Nusselt numbers and about 10% underpredicted the average Nusselt numbers. Generalized correlation for natural convection heat transfer from a horizontal cylinder with a uniform surface heat flux in liquid metals was presented based on the rigorous theoretical values for a wide range of Rayleigh numbers. It was confirmed that the correlation can describe the authors’ and other workers’ experimental data on horizontal cylinders in various kinds of liquid metals for a wide range of Rayleigh numbers. Another correlation for a horizontal cylinder with a uniform surface temperature in liquid metals, which may be applicable for special cases such as natural convection heat transfer in a sodium-to-sodium heat exchanger etc. was also presented based on the rigorous theoretical values for a wide range of Rayleigh numbers. These correlations can also describe the rigorous numerical solutions for non-metallic liquids and gases for the Prandtl numbers up to 10.     

The Japanese experiences with national PV system programmes

The paper summarises Japanese activities concerning photovoltaic systems including those for residential use, which is one of the major targets for a domestic alternative energy supply. Fiscal year 1999 marked the 25th anniversary of the Sunshine Project that was initiated in July 1974. The Sunshine Project was subsequently reorganised into the New Sunshine Program to include renewable energy, energy conservation and environmental technology. The major target of the Photovoltaic Technology Development Project in the Programme, from an early stage of R&D, has been focused on utility-connected, residential applications mounted on roofs. Recently, it can be considered that technologies for the target have been fundamentally established and a series of new activities have been introduced to promote the commercialisation and diffusion of PV systems. To review those activities, several condensed tables are presented, i.e., R&D history of residential applications, recent trends in regulation and code improvements, and new institutional activities to disseminate PV systems. The authors also present performance results collected from a large number of PV systems by using a very effective evaluation method called the ‘SV method’. The paper finishes by introducing a good example of simple system monitoring with good verification that can establish a knowledge circle from a variety of PV fields, including to factories, engineers, owners and investors, and it seems to be quite cost-effective.