Cooperative Binding of Nonionic Surfactant to Hydrophobically Modified Polyanions as Studied by Frontal Analysis Continuous Capillary Electrophoresis

The binding of a nonionic surfactant, Triton X-100 (TX), to amphiphilic copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate and N-dodecylmethacrylamide (C12) (p(A/C12(x)), where x denotes the mol % content of C12) was investigated by frontal analysis continuous capillary electrophoresis (FACCE) combined with dynamic light scattering focusing on the effect of the hydrophobe content on the binding in a wide range of x (5−60 mol %). From binding isotherms obtained from FACCE data, the binding was found to be cooperative in the whole range of x. Furthermore, a significant change in the binding behavior, i.e., cooperativity, was found to occur in a relatively narrow range of x (38−50 mol %), which is attributable to a change in the self-association behavior of p(A/C12(x)) in this x range

One-Pot Asymmetric Synthesis of β-Cyanohydroxymethyl α-Amino Acid Derivatives: Formation of Three Contiguous Stereogenic Centers

One-pot asymmetric Mannich−hydrocyanation reactions are described. Reaction of unmodified aldehydes with N-PMP-protected α-imino ethyl glyoxylate in the presence of catalytic amounts of l-proline followed by the addition of Et2AlCN provided highly enantiomerically pure β-cyanohydroxymethyl α-amino acid derivatives possessing three contiguous stereogenic centers as single diastereomers (93−99% ee). Control of reaction temperature during the cyanation step directed whether cyclization of the products to lactones occurred

Development of Novel Diastereoselective Alkenylation of Enolates Using Alkenylselenonium Salts

A novel alkenylation of enolates using alkenylselenonium salts is described. A reaction of lithium enolates, which were prepared in situ by the reaction of LiHMDS and carbonyl compounds, with alkenylselenonium salts gave the ethenylation products of carbonyl compounds in high yield. Diastereoselective alkenylation was also accomplished by the reaction of the enolates derived from N-acyl-1,3-oxazolidin-2-ones with the alkenylselenonium salt to afford good results (up to 92% yield and up to 95% de)

Development of Novel Diastereoselective Alkenylation of Enolates Using Alkenylselenonium Salts

A novel alkenylation of enolates using alkenylselenonium salts is described. A reaction of lithium enolates, which were prepared in situ by the reaction of LiHMDS and carbonyl compounds, with alkenylselenonium salts gave the ethenylation products of carbonyl compounds in high yield. Diastereoselective alkenylation was also accomplished by the reaction of the enolates derived from N-acyl-1,3-oxazolidin-2-ones with the alkenylselenonium salt to afford good results (up to 92% yield and up to 95% de)

Reactions of Diphenyl(phenylethynyl)selenonium Salts with Active Methylene Compounds and Amides: First Isolation of Oxyselenuranes [10-Se-4(C3O)] as a Reaction Intermediate

The reaction of the diphenyl(phenylethynyl)selenonium triflate 1a with active methylene compounds 5 and t-BuOK in THF gave furan derivatives 6. The [10-Se-4(C3O)] selenuranes 8a and 8b could be isolated from the reactions with benzoylacetonitrile 5f and with 1,3-indandione 5g, respectively, as reaction intermediates. The structures of the selenuranes 8 were elucidated by X-ray crystallography and 77Se high-resolution solid-state NMR spectroscopy. The selenuranes 8 underwent ligand coupling on standing at room temperature or refluxing in chloroform and gave the furan derivatives 6 and the ring-opened product 9. Similarly, the reaction of 1a with benzamide 13a and pivalamide 13d in the presence of NaH in THF afforded oxazole derivatives 14

A Highly Enantioselective Route to Either Enantiomer of Both α- and β-Amino Acid Derivatives

This report describes the unprecedented use of unmodified aldehydes as donors in a catalytic asymmetric Mannich-type reaction. The proline-catalyzed reaction of N-PMP-protected α-imino ethyl glyoxylate with unmodified aliphatic aldehydes provided a general and very mild entry to either enantiomer of β-amino and α-amino acids and derivatives in high yield and stereoselectivity. Six of the seven aldehydes studied yielded products with ee values of 99% or greater. The diastereoselectivity of the reaction increased with the bulkiness of the substituents of the aldehyde donor in the order R = Me i-Pr n-Pent. In five of the cases studied, excellent syn stereoselectivities were achieved. In addition, the corresponding chiral β-amino aldehyde adducts can be readily converted to the corresponding amino acid derivatives. Most significantly, this approach provides facile access to substituted β-lactams

A Novel Stereoselective Preparation of Various Vinyl Sulfide Derivatives Using β-Alkylthioalkenylselenonium Salts

The treatment of alkynylselenonium salt and various thiophenol derivatives with a catalytic amount of triethylamine gave β-arylthioalkenylselenonium salts in good yields. The alkenylselenonium salts thus prepared reacted with nucleophiles such as acetylides, thiolates, and alkoxides to produce (Z)-β-arylthio-α-functionalized ethenes in high yields. The vinylselenonium salts bearing a hydroxy group on a β-side chain caused intramolecular cyclization upon treatment with sodium hydride to produce medium-membered heterocyclic compounds containing sulfur and oxygen atoms. The reactions giving (Z)-β-arylthio-α-functionalized ethenes would proceed via the formation of selenurane intermediates followed by the ligand coupling reaction

Representative examples of HuR immunoreactivity in normal cells (A) and cancer cells (B) of chemical-induced bladder cancer mouse model.

<p>(Magnification, x400). Staining pattern was close to human tissues.</p

Representative examples of HuR immunoreactivity in normal urothelial cells (A; magnification, ×200.) and cancer cells (B and C; magnification, ×400.).

<p>HuR was mainly detected in nuclei of both normal and cancer cells in bladder tissues. Moderate or strong cytoplasmic expression was evident in cancer cells (C), but was rare in normal urothelial cells (A). Some cancer cells are also showed weak cytoplasmic expression although nuclear expression was detected (B). In addition, we showed representative figures of HuR expression (C) and factors related thereto; (D) cyclooxygenase-2, (E) vascular endothelial growth factor-A, (F) vascular endothelial growth factor-C in same area. (all magnification, x400).</p

Kaplan-Meier curves for recurrence-free survival rates with urinary tract cancer (A), recurrence-free survival rates with metastasis (B), and cause-specific survival rates (C).

<p>Kaplan-Meier curves for recurrence-free survival rates with urinary tract cancer (A), recurrence-free survival rates with metastasis (B), and cause-specific survival rates (C).</p