Synthesis of Naphthaleman Family Utilizing Regiocontrolled Benzannulation: Unique Molecules Composed of Multisubstituted Naphthalenes.

The naphthaleman family, a set of uniquely designed visual molecular structures comprising multisubstituted naphthalenes, was synthesized utilizing regiocontrolled benzannulation as a key step. The naphthaleman family possesses a common naphthalene body with a head comprising the 3,4-methylenedioxy group, symmetrical or unsymmetrical right and left arms, and two alkynyl legs. The synthesis involves six C-C bond-forming reaction sequences. (i) syn-Stereoselective gem-dichlorocyclopropanation of methyl angelate (86%). (ii) Acylation with ArMgBr (three examples, 60-91% yield). (iii) Stereocontrolled introduction of the 3,4-methylenedioxyphenyl group (three examples, 67-92% yield). (iv) Crucial regiocontrolled benzannulation to construct a common body segment (71-73% yield). (v) Two Suzuki-Miyaura cross-couplings to install the right or left arms (first-stage route: four examples, 77-93% and second-stage route: four examples, 42-90% yield). (vi) Double alkynylation to insert two legs (first-stage route: four examples, 61-77% yield and second-stage route: sole example, 83% yield). The four core members were produced through both first-stage and second-stage routes, with the second-stage approach demonstrating superiority over the first-stage approach. One of the members was alternatively synthesized by switching the installation order of the right and left arms, and identical twin members were produced by high-performance liquid chromatography chiral separation. The most stable conformations of two naphthaleman family members were calculated by Spartan software.

Magnetic field effects on copper metal deposition from copper sulfate aqueous solution.

Effects of a magnetic field (≤0.5 T) on electroless copper metal deposition from the reaction of a copper sulfate aqueous solution and a zinc thin plate were examined in this study. In a zero field, a smooth copper thin film grew steadily on the plate. In a 0.38 T field, a smooth copper thin film deposited on a zinc plate within about 1 min. Then, it peeled off repeatedly from the plate. The yield of consumed copper ions increased about 2.1 times compared with that in a zero field. Mechanism of this magnetic field effect was discussed in terms of Lorentz force- and magnetic force-induced convection and local volta cell formation.

Magnetic field effect on chemical wave propagation from the Belousov-Zhabotinsky reaction.

Effects of magnetic field (maximum field, 4 and 93 T(2) m(-1)) on the propagation speed of a chemical wavefront from the Belousov-Zhabotinsky reaction were studied in a thin glass tube. The downward and upward speed and the horizontal one are, respectively affected significantly by vertical and horizontal magnetic fields. Observations of the wavefront shape in magnetic fields showed that the magnetic force-induced convection causes the observed effects.

Application of partial least square on quantitative analysis of L-, D-, and DL-tartaric acid by terahertz absorption spectra.

Absorption spectra of polycrystalline L-, D-, and DL-tartaric acid have been measured by terahertz time domain spectroscopy (THz-TDS). Different absorption bands are observed for DL-tartaric acid and its enantiomers (L- and D-tartaric acid). This result shows that the THz-TDS can be used for distinguishing between DL-tartaric acid and enantiomers (L- and D-tartaric acid). Moreover, partial least square (PLS) can be found to improve the quantitation of L-tartaric acid in L- and DL-tartaric acid mixture by THz-TDS.