Y. Ueda

Establishment of a general one-pot cascade reaction protocol would dramatically reduce the effort of multistep organic synthesis. We demonstrate that the unique structure of M₁₂L₂₄ self-assembled complexes gives them the potential to serve as catalyst carriers for enabling continuous chemical transformations. A stereoselective cascade reaction (allylic oxidation followed by Diels-Alder cyclization) with two intrinsically incompatible catalysts was demonstrated. Our system i

Inflammation removes developing and mature lymphocytes from the bone marrow (BM) and induces the appearance of developing B cells in the spleen. BM granulocyte numbers increase after lymphocyte reductions to support a reactive granulocytosis. Here, we demonstrate that inflammation, acting primarily through tumor necrosis factor alpha (TNFalpha), mobilizes BM lymphocytes. Mobilization reflects a reduced CXCL12 message and protein in BM and changes to the BM environment that prevents homing by cel

Organocatalytic regioselective acylation of mono- and disaccaharides with various functionalized acid anhydrides has been developed. Acylation of octyl beta-D-glucopyranoside with acid anhydrides derived from alpha-amino acids, cinnamic acid, and gallic acid took place at C(4)-OH with 67-94% regioselectivity in the presence of catalyst 1. Regioselective acylation of disaccharides with functionalized acid anhydrides was also achieved with 78-94% selectivity. Especially, a disaccharide with seven

Acylation of lanatoside C in the presence of organocatalyst 5 gave the C(4'''')-O-acylate in up to 90% regioselectivity (catalyst-controlled regioselectivity). Various functionalized acyl groups can be introduced at the C(4'''')-OH by a mixed anhydride method in the presence of 5 or the related organocatalyst. On the other hand, DMAP-catalyzed acylation of lanatoside C gave the C(3'''')-O-acylate in up to 97% regioselectivity (substrate-controlled regioselectivity). Thus, diverse regioselective

The first total syntheses of multifidosides A-C have been achieved. The synthetic strategy is characterized by catalytic site-selective acylation of unprotected glycoside precursors in the final stage of the synthesis. High functional-group tolerance of the site-selective acylation, promoted by an organocatalyst, enabled the conventionally difficult molecular transformation in a predictable and reliable manner. An advantage of this strategy is to avoid the risks of undesired side reactions durin

The first total syntheses of punicafolin (1) and macaranganin (2) were achieved in seven steps, respectively, from commercial α-d-glucose. The characteristic features of the synthesis are (1) sequential site-selective introduction of the adequate galloyl groups into unprotected d-glucose by a catalyst-controlled manner and (2) stereodivergent construction of the 3,6-HHDP bridge by oxidative phenol coupling of a common intermediate via a ring-flipping process of the glucose core. Because no prote

A total of 90 strains of Actinobacillus pleuropneumoniae isolated from porcine pneumonic lungs in Japan during 1989 to 1993 were investigated for their in vitro susceptibility to florfenicol (a derivative of thiamphenicol) and other drugs. The minimal inhibitory concentrations of florfenicol against A. pleuropneumoniae ranged from 0.2 to 1.56 micrograms/ml with a peak at 0.39 microgram/ml. Florfenicol showed a high antibacterial activity against A. pleuropneumoniae regardless of the sensitivity

Intermolecular aromatic C(sp²)-H amination promoted by neutral rhodium nitrenoids has been developed. The reactions proceeded with various oxygen-substituted arenes (1.5 equiv.) in a chemo- and regioselective manner. The aromatic C(sp²)-H amination took place at the para position of the oxygen substituent in the presence of benzylic C(sp³)-H bonds and/or C(sp³)-H bonds α to ethereal oxygen.

Magnetoresistance (MR) has been investigated for the compacts of the Co20Cu80 mixture powders prepared by the mechanical alloying (MA) method. The crystal structure and the magnetic properties of the as-milled and the annealed samples have been examined for various milling times. The MR ratio depends on both the annealing temperature (400–550°C) and the annealing time (0–20 h). Moreover, the MR ratio depends on the milling time. The maximum MR ratio shows 6.7% (1.2 MA/m) and 7.4% (1.6 MA/m) at m

A two-step procedure was developed for the synthesis of 4-deoxy pyranosides from the parent pyranosides with four hydroxy groups via organocatalytic site-selective acylation and reductive deacyloxylation.