Polymerization of p‐n‐hexyloxyphenylacetylene (pHPA) by using a [Rh(norbornadine)Cl]2‐triethylamine catalyst was carried out at room temperature to afford stereoregular helical poly(p‐n‐hexyloxyphenylacetylene)s (PpHPAs). When ethanol and n‐hexane were used as polymerization solvents, a bright yellow PpHPAs, poly(Y) with Mn = 8.5 × 104 and its purple red polymer, poly(R) with Mn = 5.3 × 104 were obtained in 95% yields and 84% yields, respectively. Diffuse reflective UV–vis spectra of poly(Y) and poly(R) in solid phase showed different broad absorption peaks at 445 and 575 nm, respectively. X‐Ray diffraction patterns of poly(Y) and poly(R) showed typical columnar structures assignable to cis‐transoid and cis‐cisoid structures, respectively, which were also supported by molecule mechanics calculation. Poly(Y) was irreversibly transformed to a reddish‐black polymer, poly(Y‐B), which columnar diameter was nearly the same as that of poly(R). Further, poly(Y) showed an exothermic peak in the differential scanning calorimetry trace at 80 °C for 1 h in N2 gas. Thus, these findings suggest a thermally irreversible rearrangement from an unstable cis‐transoid form, poly(Y) with a stretched cis‐transoid helix to a stable cis‐cisoid form, poly(R), with a contracted cis‐cisoid helix in the solid phase to give poly(Y→B) with the cis‐cisoid form. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Amyloid-β aggregation inhibitors are expected to be therapeutic or prophylactic agents for Alzheimer's disease. Rosmarinic acid, which is one of the main aggregation inhibitors derived from Lamiaceae, was employed as a lead compound and its 25 derivatives were synthesized. In this study, the structure-activity relations of rosmarinic acid derivatives for the amyloid-β aggregation inhibitory effect (MSHTS assay), antioxidant properties, and xanthine oxidase inhibition were evaluated. Among the tested compounds, compounds 16d and 19 were found to the most potent amyloid aggregation inhibitors. The SAR revealed that the necessity of the presence of the phenolic hydroxyl on one side of the molecule as well as the lipophilicity of the entire molecule. The importance of these structural properties was also supported by docking simulations.

Enantioselective Diels-Alder reactions of 1,2-dihydropyridines with acroleins using a novel chiral oxazolidine organocatalyst afforded chiral isoquinuclidines that is an efficient synthetic intermediate of oseltamivir, with fairly good chemical yield and excellent enantioselectivity (90%, up to >99% ee).

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Chiral primary β‐amino alcohols, constuting adjacently positioned Brønsted base and Brønsted acid sites, are emerging as very valuable bifunctional organocatalysts in a wide array of asymmetric organic transformations. Primary β‐amino alcohols represent inexpensive alternatives to other primary amino organocatalysts such as chiral diamines and cinchona‐alkaloid‐derived primary amines, being easy to synthesize and air‐stable and offering the potential for introduction of different functional groups and also for alteration of steric sites. Here we reveal the catalytic use of simple primary β‐amino alcohols and their derivatives as organocatalysts in Diels–Alder cycloaddition, aldol condensation, Michael addition, 1,3‐dipolar cycloaddition, the Morita–Baylis–Hillman reaction, cascade cyclization, allylation of isatins, Friedel–Crafts alkylation and epoxidation of olefins.