Chirality control in oligothiophene through chiral wrapping

[structure: see text] Mixing oligothiophenes and polysaccharides, such as amylose and schizophyllan, affords novel inclusion complexes, in which oligothiophene guests adopt twisted conformation in the chiral channel created by left- or right-handed helical wrapping with the polysaccharide host polymers, leading to optical activity.     

First enantioselective synthesis of salinipostin A,a marine cyclic enol-phosphotriester isolated from Salinispora sp

Salinipostins are cyclic enol-phosphotriesters isolated from a marine-derived Salinispora sp. as antimalarial compounds. Herein, the first enantioselective synthesis of salinipostin A was achieved. Organocatalyst-mediated asymmetric cyclopropanation and regioselective cyclopropane ring opening were the key steps.     

Base-mediated cyclization reaction of 2-alkynylphenylphosphine oxides: synthesis and photophysical properties of benzo[b]phosphole oxides

The base-mediated intramolecular cyclization reaction of 2-alkynylphenylphosphine oxides affords benzo[ b]phosphole oxides, which show intense blue-green fluorescence. Benzo[ b]phospholes are also prepared by the reduction of benzo[ b]phosphole oxides.     

Weak-type Estimates and Potential Estimates for Elliptic Equations with Drift Terms

We consider divergence form elliptic equations with a strongly singular drift term ?d i v(A?u)+b??u=μ in a domain \({\Omega } \subset \mathbb {R}^{n}\) (n≥3). We give a weak-type \(L^{1} - L^{n / (n - 2), \infty }\) estimate for a solution to the Dirichlet problem with homogeneous boundary condition. Moreover, we give a two-sided pointwise potential estimate for a weak solution and its applications.     

The Wolff potential estimate for solutions to elliptic equations with signed data

In this note, we obtain sharp bounds for the Green’s function of the linearized Monge–Ampère operators associated to convex functions with either Hessian determinant bounded away from zero and infinity or Monge–Ampère measure satisfying a doubling condition. Our result is an affine invariant version of the classical result of Littman–Stampacchia–Weinberger for uniformly elliptic operators in divergence form. We also obtain the L ^p integrability for the gradient of the Green’s function in two dimensions. As an application, we obtain a removable singularity result for the linearized Monge–Ampère equation.     

Consecutive disilanylsilylene to silyldisilene rearrangements

Thermolysis of 2,3-benzo-1,4-diphenyl-7-silanorbornadiene derivatives 1 in the presence of 2,3-dimethylbutadienes gave the trapping products of the corresponding bissilylene, disilenylsilylene, and a tetrasila-1,3-butadiene, via a consecutive disilanylsilylene to silyldisilene rearrangement.     

Determination of very volatile organic compounds in environmental water by injection of a large amount of headspace gas into a gas chromatograph

An injection method for a large amount of headspace gas which enables determination of trace amounts of very volatile organic compounds (VVOCs), dichlorodifluoromethane, chloromethane, vinyl chloride, bromomethane, chloroethane and trichlorofluoromethane in all kinds of environmental water was developed. A gas phase equilibrated with the water phase in a vial was purged with helium for a short time. The VVOCs were then introduced into a trapping tube packed with Tenax TA, which had been cooled using carbon dioxide. After trapping, the VVOCs were thermally desorbed and put into a GC–MS system for subsequent analysis. This method is applicable to various types of samples.     

Transition-metal-free controlled polymerization for poly(p-aryleneethynylene)s

A transition-metal-free controlled polymerization for the attainment of poly(p-aryleneethynylene)s is developed. The polymerization of 1-pentafluorophenyl-4-[(trimethylsilyl)ethynyl]benzene with a catalytic amount of fluoride anions proceeds in a chain-growth-like manner to afford polymers with controlled molecular weights and low polydispersity indexes. The mechanism involves a pentacoordinated fluorosilicate as a key intermediate. The anionic “living” nature of this process is applied to block copolymerization and also surface-terminated polymerization.