Scandium triflate-catalyzed 6,6′-diiodination of 2,2′-dimethoxy-1,1′-binaphthyl with 1,3-diiodo-5,5-dimethylhydantoin

Scandium triflate-catalyzed iodination of 2,2′-dimethoxy-1,1′-binaphthyl with 2 equiv of 1,3-diiodo-5,5-dimethylhydantoin (DIH) proceeded to give 6,6′-diiodo-2,2′-dimethoxy-1,1′-binaphtyl in 98% yield and subsequent deprotection of methyl groups provided 6,6′-diiodo-1,1′-binaphthol, which is a useful ligand or reagent for many enantioselective transformations. Use of 2 equiv of NIS in place of DIH in the presence of scandium triflate, however, did not successfully yield 6,6′-diiodo-2,2′-dimethoxy-1,1′-binaphtyl, indicating that one of two types of iodine atoms in DIH is more reactive toward the iodination than iodine in NIS.     

Synthesis and evaluation of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety as selective β3-adrenergic receptor agonists

In the search for potent and selective human β3-adrenergic receptor (AR) agonists as potential drugs for use in treating obesity and non-insulin dependent (type 2) diabetes, a series of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety were prepared and their biological activities against human β3-, β2-, and β1-ARs were evaluated. Among these compounds, N-phenyl-(2-phenylaminothiazol-4-yl)acetamide (4 g), N-phenyl-(2-benzylaminothiazol-4-yl)acetamide (4j), and N-phenyl-[2-(3-methoxyphenyl)aminothiazol-4-yl]acetamide (6g) derivatives showed potent agonistic activity against the β3-AR with functional selectivity over the β1- and β2-ARs. In addition, these compounds exhibited significant hypoglycemic activity in a rodent model of diabetes.     

Molecular symmetry and biological activities of new symmetrical tris(2-aminoethyl)amine derivatives

In terms of molecular symmetry and bioactivity, new C3- and CS-symmetrical derivatives based on the tris(2-aminoethyl)amine scaffold were designed and synthesized. The synthesized compounds were evaluated for antiviral activity with herpes simplex virus type 1 (HSV-1) by a plaque reduction assay and for cytotoxic activity with Vero cells. Most of the compounds showed no significant anti-HSV-1 activity, but some of the symmetrical derivatives showed high levels of cytotoxic activitiy.     

Aggregation of 1-dodecyl-3-methylimidazolium nitrate in water and benzene studied by SANS and 1H NMR

Aggregation of imidazolium-based ionic liquid, C(12)mim(+)NO(3)(-), in both polar solvent of water and nonpolar solvent of benzene was elucidated by electrical conductivity, small-angle neutron scattering (SANS), and (1)H NMR measurements. The electrical conductivities of C(12)mim(+)NO(3)(-)-water solutions at 298 K as a function of ionic liquid concentration showed a break point at 8.4 mmol dm(-3) as a cmc. However, those of C(12)mim(+)NO(3)(-)-benzene solutions drastically increase in accordance with a cubic function of concentration, but without a break point. The SANS profiles of both aqueous and benzene solutions obviously differ from each other. The profiles of the aqueous solutions indicated the formation of polydisperse spherical micelles. Those of the benzene solutions revealed Ornstein-Zernike behavior. Thus, C(12)mim(+)NO(3)(-) forms clusters in the benzene solutions, but the shape of clusters is indefinite. On the basis of the (1)H NMR chemical shifts of the aqueous solutions, the effect of nitrate on the formation of micelles was discussed on a microscopic scale. Furthermore, the interactions among C(12)mim(+), NO(3)(-), and benzene molecules in the benzene solutions were considered according to the (1)H NMR data.     

Supramolecular-tilt-chirality on twofold helical assemblies

A twofold helix (2(1) helix) is an essential motif in approximately 70?% of organic crystals. Although handedness of 2(1) helix has not been discussed from a mathematical viewpoint, we noticed that the handedness can be defined by considering the molecular shape and manner of assembly. Herein we propose the supramolecular-tilt-chirality (STC) method to define the handedness, and illustrate it by way of some examples. We believe that establishment of the systematic rules for supramolecular chirality will contribute to the progression of supramolecular chemistry and material science.     

The Bioassay-Guided Isolation of Growth Inhibitors of Adult T-Cell Leukemia (ATL), from the Jamaican Plant <em>Hyptis verticillata</em>, and NMR Characterization of Hyptoside

Through bioassay-guided isolation, five compounds with growth inhibitory activity on S1T, an adult T-cell leukemia (ATL) cell line, were isolated from the crude methanol extract of the aerial parts of Hyptis verticillata.     

Hydrogen‐Bonding‐Induced Chirality Organization and Stabilization of Redox Species of Polyaniline‐Unit Molecules by Introduction of Amino Acid Pendant Groups

The chirality organization of polyaniline‐unit molecules was achieved by the introduction of amino acid pendant groups through intramolecular hydrogen bonding, which plays an important role in the stabilization of the chirality‐organized redox species. Another interesting feature of the synthesized polyaniline‐unit molecules is the luminescent switching properties based on the redox states of the phenylenediamine moiety.     

Putting the 'N' in ACENE: pyrazinacenes and their structural relatives

Acenes have emerged as an important class of organic electronic material. Related heteroatom-substituted compounds, or heteroacenes, introduce an important means for modulating properties and improving materials' stability. In this perspective, we will review the historical origins of the heteroacenes and discuss recent progress in the field of acene and related compounds containing fused 1,4-diazabenzene units, i.e. pyrazine, also known as the 'pyrazinacenes'. We focus not only on the types of materials that have been prepared but also on their chemical and physical properties, including synthetic procedures, electronic properties, self-assembly characteristics, and we also introduce some of the computational studies aimed at understanding the more unusual behaviours of this group of compounds, such as protic tautomerism and aromaticity/antiaromaticity.     

Stereoselective coupling reaction of dimethylzinc and alkyne toward nickelacycles

Ni catalyst promotes the three-component coupling reaction of vinyloxacyclopropane, alkyne, and dimethylzinc to provide 2,5-heptadienyl alcohol in high yields. Vinylcyclopropane also participates in a similar three-component coupling reaction to afford dimethyl (α-heptadienyl)malonate with excellent E-stereoselectivity.     

Enantioselective total synthesis of aperidine

An efficient total synthesis of aperidine was accomplished using a Rh-catalyzed C-H insertion of a cis-dihydrobenzofuran ring. To circumvent the facile epimerization of the cis-dihydrobenzofuran ring, we designed and prepared the C-H insertion precursor diazoamide by Raines' protocol. Finally, the efficient incorporation of a guanidine group and mild deprotection conditions yielded this labile natural product.