A Designer Axially Chiral Amino Sulfonamide as an Efficient Organocatalyst for Direct Asymmetric anti‐Selective Mannich Reactions and syn‐Selective Cross‐Aldol Reactions

Amino sulfonamide catalyst : A distal proton of the axially chiral amino sulfonamide (S)‐ 1 realized the opposite diastereoselectivity in Mannich and cross‐aldol reactions compared with that observed in proline‐catalyzed reactions. The reactions catalyzed by (S)‐ 1 proceeded smoothly to give the anti‐Mannich and syn‐aldol adducts in excellent enantioselectivity (see scheme).

     

Digital Staining of Unstained Pathological Tissue Samples through Spectral Transmittance Classification

Histological structures of a pathological tissue sample convey information relevant to the diagnosis of the disease that might have afficted the person. To reveal the morphology of these structures clearly, pathological tissues are stained. In this paper, a digital staining methodology for pathological tissue samples is introduced. Digital staining implies the application of digital processing techniques to transform the image of an unstained sample to its stained image counterpart. In the method, the transmittance spectra of the unstained and Hematoxylin and Eosin (H&E) stained multispectral images (16 bands) of specific tissue components are utilized. Two experiments were conducted to probe the possibility of the digital staining framework: the linear mapping of spectral transmittances, and the classification of spectral transmittances in conjunction with the linear mapping of specific transmittance data sets. The method classified the four tissue components, e.g. nucleus, cytoplasm, red blood cells, and the white region (region devoid of tissue structures), while the misclassifications between components with spectral transmittances that are closely similar were not completely rectified. © 2005 The Optical Society of Japan     

Urinary metabolites of nobiletin orally administered to rats

During the course of our systematic investigation of the metabolism of flavonoids, the polymethoxyflavone nobiletin, occurring in the fruits of Citrus depressa, was orally administered to rats. The urinary metabolites were separated and identified by three-dimensional HPLC equipped with a photodiode array detector and the structure was determined by spectroscopic methods to be 4'-hydroxy-3',5,6,7,8-pentamethoxyflavone (1).     

A new synthesis of pyrimido[5,4-e]-as-triazine 4-oxides and their ring transformation to pyrrolo[3,2-d]pyrimidines

A new synthesis of certain pyrimido[5,4-e]-as-triazine 4-oxides and their ring transformation to pyrrolo-[3,2-d]pyrimidines by the 1,3-dipolar cycloaddition reaction is described. Thus, reaction of 6-hydrazino-1,3-dimethyluracil ( 1 ) with triethyl orthoformate gave 6-ethoxymethylenehydrazino-1,3-dimethyluracil ( 2 ). Treatment of 2 with arylamines gave 6-arylaminomethylenehydrazino-1,3-dimethyluracils ( 3a-e ). Nitrosative cyclization of 3a-e with sodium nitrite afforded 3-arylaminofervenulin 4-oxides ( 6a-e ). Reaction of 6a-e with acetylenic esters yielded 7-alkoxycarbonyl-6-arylamino-1,3-dimethylpyrrolo[3,2-d]pyrimidine-2,4(1H,3H-diones ( 15a-e and 16 ).     

Synthesis of cyclic dienamide using ruthenium-catalyzed ring-closing metathesis of ene-ynamide

[reaction: see text] Ring-closing metathesis of ene-ynamide using the second-generation Grubbs' catalyst produced nitrogen-containing heterocycles, which have dienamide moieties, in high yields. Diels-Alder reaction of the cyclized product and dienophile proceeded smoothly to afford a bi- or tricyclic compound.     

1-tert-butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline: a novel and chemoselective tert-butoxycarbonylation reagent

[reaction: see text] The use of 1-tert-butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline (BBDI) as tert-butoxycarbonylation reagent for aromatic and aliphatic amine hydrochlorides and phenols in the absence of a base has been demonstrated. The reactions proceed chemoselectively in high yield under mild conditions.     

Atomic-layer resolved magnetic and electronic structure analysis of ni thin film on a Cu(001) surface by diffraction spectroscopy

Up until now there has been no direct method for detecting the electronic and magnetic structure of each atomic layer at the surface, which is an essential analysis technique for nanotechnology. For this purpose, we have developed a new method, diffraction spectroscopy, based on the photon energy dependence of the angular distribution of Auger electron emission. We have applied this method to analyze the magnetic structure of a Ni ultrathin film on a Cu(001) surface around the spin reorientation transition. Atomic-layer resolved x-ray absorption and magnetic circular dichroism spectra were obtained. Surface and interior core-level shifts and magnetic moments are determined for each atomic layer individually.