A new titanium tetrachloride mediated annulation of alpha-aryl-substituted carbonyl compounds with alkynes: A simple and highly efficient method for the regioselective synthesis of polysubstituted naphthalene derivatives

A new straightforward procedure has been developed for the synthesis of polysubstituted naphthalene derivatives. The reaction of alpha-aryl-substituted carbonyl compounds with terminal or internal alkynes in the presence of TiCl4 regioselectively generates substituted naphthalene derivatives in good to excellent yields.     

Regioselective construction of polysubstituted phenols from Baylis-Hillman adducts via formal [4+2] annulation strategy

Polysubstituted phenol derivatives were synthesized regioselectively starting from the Baylis-Hillman adducts via the formal [4+2] annulation protocol as the key step.     

Electrochemical determination of electroinactive guests of β-cyclodextrin at a self-assembled monolayer interface

A novel determination method of electroinactive molecules by means of electrochemical technique is presented. A new self-assembled monolayer containing cyclodextrin (CD) is prepared with mono(6-o-p-tolylsulfonyl)-β-cyclodextrin. Although this derivatization process leads to a β-CD coverage of 10% of a full monolayer, this layer shows an effective host-guest response to ferrocene. The interfacial ferrocene complexation gives a response similar to that expected for a Langmuir adsorption isotherm yielding a stability constant of 4.2 ×104 mol-1· L and a maximum ferrocene coverage of 8.6×10-12 mol/cm2. The redox peak currents of the surface-confined ferrocene decrease upon addition of competing β-CD guest species to the solution, such as m-toluic acid (mTA) and sodium dodecyl sulfonate (SDS). This principle has been used for the determination of the electroinactive molecules, mTA and SDS in the concentration ranges of 0.8-2.7 μmol/L and 5-100 nmol/L, respectively.     

Synthesis, characterization and single crystal structures of one-dimensional coordination polymers formed with [Ni(L)]·2ClO4 and polycarboxylate ligands

Two new one-dimensional coordination polymers {[Ni(L)(maleate)] · H₂O} _n (1) and {[Ni(L)(H₂btc)] · 2DMF} _n (L = cyclam, btc = 1,2,4,5-benzenetetracarboxylate, DMF = N,N-dimethylformamide) (2) have been synthesized and structurally characterized by single crystal X-ray diffraction. In the structures (1) and (2), the carboxylate groups of bridging ligands are coordinated to nickel(II) cyclams resulting in the formation of one-dimensional coordination polymers. In addition to the Ni–O bonds, it is observed that the hydrogen bonding interactions between the pre-organized N–H groups of the cyclams and bridging anions support the formation of coordination polymers in both complexes.     

Sensitive determination of heroin based on electrogenerated chemiluminescence of tris(2,2'-bipyridyl)ruthenium(II) immobilized in zeolite Y modified carbon paste electrode

A novel method for rapid, inexpensive, sensitive and selective determination of heroin was proposed by flow injection electrogenerated chemiluminescence (ECL). Zeolite Y sieves were used for the preparation of a ECL sensor by immobilizing tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+)) in their supercages, which was achieved through the ion exchange properties of the sieves. The electrochemical and ECL behaviors of Ru(bpy)3(2+) immobilized in zeolite Y modified carbon paste electrode was investigated. The immobilized Ru(bpy)3(2+) displayed a pair of surface-controlled redox peaks with an electron transfer rate constant of 1.2 +/- 0.1 s(-1) in 0.1 mol dm(-3) pH 6.3 phosphate buffer. The modified electrode showed an electrocatalytic response to the oxidation of heroin, producing a sensitized ECL signal. The ECL sensor showed a linear response to flow injection of heroin in the range of 2.0-80 micromol dm(-3) with a detection limit of 1.1 micromol dm(-3). This method for heroin determination possessed good sensitivity and reproducibility with a coefficient of variation of 1.99% (n = 15) at 50.0 micromol dm(-3). The ECL sensor showed good selectivity and long-term stability. Its surface could be renewed quickly and reproducibly by a simple polish step.     

Dynamic Behavior and Mass Transport in Polyacrylic Acid Gel by Dynamic Light Scattering

Dynamic behaviors on polyacrylic acid (PAA) gels and mass (small molecules) transports in the gels have been studied mainly by dynamic light scattering (DLS). The cross-linking degree (fc), monomer concentration (Cm) and temperature of the gels have significant influences on its dynamic behavior and mass transport in the gels. The increase of fc leads to decrease of the mesh sizes of the gels, thus the obstacle of the gels for mass thansport is increased. As a result, small molecular diffusion Dk in the gles is decreased.So even if for small molccules, the Dk also is influenced.     

Synthesis of substituted quinoline via copper-catalyzed one-pot cascade reactions of 2-bromobenzaldehydes with aryl methyl ketones and aqueous ammonia

In this Letter, a new version of the Friedländer synthesis of quinoline derivatives starting from 2-bromobenzaldehydes, aryl methyl ketones, and aqueous ammonia with copper-catalyzed amination as a key step is presented. Remarkable advantages of this new quinoline synthesis include commercially available and economical starting materials, simple operational process, and excellent efficiency.     

Naphthodithiophene‐Diketopyrrolopyrrole‐Based donor–Acceptor alternating π‐Conjugated polymers for Organic thin‐Film transistors

Novel naphtho[1,2‐b:5,6‐b′]dithiophene (NDT) and diketopyrrolopyrrole (DPP)‐containing donor‐acceptor conjugated polymers (PNDTDPPs) with different branched side chains were synthesized via Pd(0)‐catalyzed Stille coupling reaction. Octyldodecyl (OD) and dodecylhexadecyl (DH) groups were tethered to the DPP units as the side chains. The soluble fraction of PNDTDPP‐OD polymer in chloroform has much lower molecular weight than that of PNDTDPP‐DH polymer. PNDTDPP‐DH polymer bearing relatively longer DH side chains exhibited much better charge‐transport behavior than PNDTDPP‐OD polymer with shorter OD side chains. The thermally annealed PNDTDPP‐DH polymer thin films exhibited an outstanding charge carrier mobility of ～1.32 cm² V^?1 s^?1 (I_on/I_off ～ 10⁸) measured under ambient conditions, which is almost six times higher than that of thermally annealed PNDTDPP‐OD polymer thin films. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5280–5290