Metal-free visible-induced C(sp)-C(sp) coupling of quinoxalin-2()-ones oxidative cleavage of the C-N bond.

A C(sp)-C(sp) reaction between aromatic hydrazines and quinoxalines has been developed through a photocatalytic system. The protocol is established for C(sp)-N bond cleavage and direct C(sp)-H functionalization for the coupling of C(sp)-C(sp) photocatalysis under mild and ideal air conditions without the presence of a strong base and metal. The mechanistic studies reveal that the generation of a benzene radical the oxidative cleavage of aromatic hydrazines for the cross-coupling of C(sp)-C(sp) with the assistance of a photocatalyst is essential.

DIPEA-induced activation of OH for the synthesis of amides photocatalysis.

The development of green protocols for photocatalysis where water acts as a nucleophile, induced by a weak organic base, is difficult to achieve in organic chemistry. Herein, an efficient light-mediated strategy for the synthesis of amides in which a weak organic base acts as a reductant to induce the formation of OH- from water under metal-free conditions is reported. A mechanistic study reveals that the generation of an ,-diisopropylethylamine (DIPEA) radical single electron transfer (SET), with the assistance of photocatalyst, that increases the nucleophilicity of the water molecules with respect to the cyanides is essential.

Electro-oxidative cyclization: access to quinazolinones KSO without transition metal catalyst and base.

A KSO-promoted oxidative tandem cyclization of primary alcohols with 2-aminobenzamides to synthesize quinazolinones was successfully achieved under undivided electrolytic conditions without a transition metal and base. The key feature of this protocol is the utilization of KSO as an inexpensive and easy-to-handle radical surrogate that can effectively promote the reaction a simple procedure, leading to the formation of nitrogen heterocycles direct oxidative cyclization at room temperature in a one-pot procedure under constant current. Owing to the use of continuous-flow electrochemical setups, this green, mild and practical electrosynthesis features high efficiency and excellent functional group tolerance and is easy to scale up.

Electrochemically induced synthesis of quinazolinones via cathode hydration of o-aminobenzonitriles in aqueous solutions.

An efficient and practical electrochemically catalyzed transition metal-free process for the synthesis of substituted quinazolinones from simple and readily available o-aminobenzonitriles and aldehydes in water has been accomplished. I/base and water play an unprecedented and vital role in the reaction. By electrochemically catalysed hydrolysis of o-aminobenzonitriles, the synthesis of quinazolinones with benzaldehyde was first proposed.

[Synthesis and application of a surface molecularly imprinted adsorbent for di(2-ethylhexyl)phthalate base on graphite oxide].

A molecularly imprinted polymer (MIP) base on the surface of graphite oxide (GO) has been developed for the selective recognition of di(2-ethylhexyl)phthalate (DEHP), and applied for the extraction of DEHP in a milk bag sample, with detection by high-performance liquid chromatography. The surface-molecularly imprinted material was prepared by precipitation polymerization in -dimethylformamide (DMF) solvent, using GO as the supporting material, DEHP as the template molecule, and methacrylic acid (MAA) as the functional monomer; the synthesis conditions were also optimized. The obtained GO-MAA-MIP was characterized by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM).

[Preparation of octadecyl methacrylate-based polymer stationary phase by in-situ polymerization for open tubular capillary electrochromatography].

The preparation of porous polymethacrylate-based open tubular capilary columns by in-situ copolymerization of octadecyl methacrylate (OMA), and ethylene dimethacrylate (EDMA) in N,N-dimethylformamide (DMF) solvent are proposed. The parameters of the preparation procedure of the stationary phase are discussed in detail. The surface of the cross-section of an open tubular (OT) column by scanning electron microscope (SEM) showed wrinkle configuration, which is expedient to enhance proportion of stationary phase and column capacity.

[Preparation and evaluation of open tubular capillary electrochromatographic column modified with carboxymethyl chitosan].

Via covalent coupling of epoxy group, an open tubular column covalently modified with carboxymethyl chitosan (CMC) as stationary phase was prepared. The parameters of column pretreatment, silanization and chemically bonding of CMC were optimized. The morphology of inner wall of the open tubular column was observed by scanning electron microscope (SEM), which showed that the inner wall of the prepared column was evenly coated with a polymer film.

Carboxymethylchitosan covalently modified capillary column for open tubular capillary electrochromatography of basic proteins and opium alkaloids.

A novel open tubular (OT) column covalently modified with hydrophilic polysaccharide, carboxymethylchitosan (CMC) as stationary phase has been developed, and employed for the separations of basic proteins and opium alkaloids by capillary electrochromatography (CEC). With the procedures including the silanization of 3-aminopropyltrimethoxysilane (APTS) and the combination of glutaraldehyde with amino-silylated silica surface and CMC, CMC was covalently bonded on the capillary inner wall and exhibited a remarkable tolerance and chemical stability against 0.1 mol/L HCl, 0.