Easy S-Alkylation of Arylthioureas and 2-Mercaptobenzothiazoles Using Tetraalkylammonium Salts under Transition-Metal-Free Conditions.

A highly-efficient and practical method for S-alkylation of arylthioureas was reported. Using tetraalkylammonium salts as alkylation reagents, a series of 68 S-substituted aryl-isothioureas were obtained in good to excellent yields under transition-metal-free conditions. The protocol features simple performance, broad functional group tolerance, good to excellent yields, and easily available starting materials, showing potential synthetic value for the preparation of diverse biologically or pharmaceutically active compounds.

One-Pot Synthesis of 1,2-Disubstituted Indoles from 2-Ethynylanilines and Benzaldehydes.

An efficient synthesis of a variety of 1,2-disubstituted indoles from 2-ethynylanilines was developed. Using 2-ethynylanilines and benzaldehydes as starting materials, the target products (1,2-disubstituted indoles) were obtained smoothly through condensation, reduction, and subsequent cyclization. Various functional groups attached to the aryl ring of 1,2-disubstituted indoles were well tolerated. The protocol features easy performance, easily available starting materials, good yield, and a broad substrate scope, showing potential synthetic value for the preparation of a variety of biologically or pharmaceutically active compounds.

One-Pot Synthesis of N,N-Diphenyl-2-benzothiazolamines from 1-(2-Iodophenyl)-3-phenylthioureas and Iodobenzenes.

An efficient copper-catalyzed synthesis of a variety of N,N-diphenyl-2-benzothiazolamines was developed. Starting from substituted 1-(2-iodophenyl)-3-phenylthioureas and substituted iodobenzenes, the reaction proceeded smoothly via a tandem manner in the presence of CuI to afford the corresponding N,N-diphenyl-2-benzothiazolamine derivatives with good functional group tolerance. The protocol features simple performance, easily available starting materials, a one-pot manner, and good functional group tolerance, providing a practical strategy for the preparation of poly-functionalized amines.

Synthesis of Unsymmetric Thiosulfonates Starting from N-Substituted O-Thiocarbamates: Easy Access to the S-SO2 Bond.

Using phenyliodine diacetate as an oxidant and nickel acetate as a promoter, a wide range of unsymmetric thiosulfonates could be furnished easily in moderate to excellent yields starting from N-substituted O-thiocarbamates and sodium sulfinates. This protocol features mild conditions, short reaction times, and high atomic utilization, which can provide an alternative method for the synthesis of unsymmetric thiosulfonates. In addition, the reaction could be scaled up on a gram scale, showing potential application value in industry.

One-Pot Synthesis of Benzoazole-Substituted Thioenamines via a Cross Dehydrogenation Coupling (CDC) Reaction.

An iodine-catalyzed synthesis of benzoazole-substituted thioenamines in a one-pot manner was reported. Using 2-aminothiophenols (or 2-aminophenols or 1,2-phenylenediamines), tetramethylthiuram disulfide (TMTD), and enamines (mainly indoles) as starting materials, the target C(sp2)-S formation products (benzoazole-substituted thioenamines) could be furnished smoothly in good yields. The reaction might proceed through an electrophilic substitution pathway in a cross dehydrogenation coupling (CDC) manner. The protocol is metal-free and features easy performance, a one-pot manner, a good functional group tolerance, and good yields.

Cs2CO3-Promoted Hydrothiolation of Alkynes with Aryl Thioureas: Stereoselective Synthesis of (Z)-Vinyl Sulfides.

A metal-free Cs2CO3-promoted hydrothiolation of alkynes with aryl thioureas for stereoselective synthesis of (Z)-vinyl sulfides has been reported. Vinyl thioethers were obtained without a metal catalyst in good yields via anti-Markovnikov and cis addition. The protocol features a broad substrate scope of the starting materials, high atom economy, good yields, and exclusive stereoselectivity, showing potential synthetic value for the synthesis of a diversity of (Z)-vinyl thioethers.

Titanium catalyzed [2σ + 2π] cycloaddition of bicyclo[1.1.0]-butanes with 1,3-dienes for efficient synthesis of stilbene bioisosteres.

Natural stilbenes have shown significant potential in the prevention and treatment of diseases due to their diverse pharmacological activities. Here we present a mild and effective Ti-catalyzed intermolecular radical-relay [2σ + 2π] cycloaddition of bicyclo[1.1.0]-butanes and 1,3-dienes. This transformation enables the synthesis of bicyclo[2.1.1]hexane (BCH) scaffolds containing aryl vinyl groups with excellent regio- and trans-selectivity and broad functional group tolerance, thus offering rapid access to structurally diverse stilbene bioisosteres.

A classical but new kinetic equation for hydride transfer reactions.

A classical but new kinetic equation to estimate activation energies of various hydride transfer reactions was developed according to transition state theory using the Morse-type free energy curves of hydride donors to release a hydride anion and hydride acceptors to capture a hydride anion and by which the activation energies of 187 typical hydride self-exchange reactions and more than thirty thousand hydride cross transfer reactions in acetonitrile were safely estimated in this work. Since the development of the kinetic equation is only on the basis of the related chemical bond changes of the hydride transfer reactants, the kinetic equation should be also suitable for proton transfer reactions, hydrogen atom transfer reactions and all the other chemical reactions involved with breaking and formation of chemical bonds. One of the most important contributions of this work is to have achieved the perfect unity of the kinetic equation and thermodynamic equation for hydride transfer reactions.

(E)-1-Phenyl-3-[4-(trifluoro-meth-yl)phen-yl]prop-2-en-1-one.

In the title compound, C(16)H(11)F(3)O, the dihedral angle between the two rings is 48.8 (2)°. The crystal packing exhibits no classical inter-molecular inter-actions between the mol-ecules.

3-Nitro-2-phenyl-chroman.

In the title compound, C(15)H(13)NO(3), the dihedral angle between the two aromatic rings is 79.25 (16)°.

Design, Synthesis, and Activity Evaluation of Novel Acyclic Nucleosides as Potential Anticancer Agents In Vitro and In Vivo.

In the present work, 103 novel acyclic nucleosides were designed, synthesized, and evaluated for their anticancer activities in vitro and in vivo. The structure-activity relationship (SAR) studies revealed that most target compounds inhibited the growth of colon cancer cells in vitro, of which 3-(6-chloro-9H-purin-9-yl)dodecan-1-ol (9b) exhibited the most potent effect against the HCT-116 and SW480 cells with IC50 values of 0.89 and 1.15 µM, respectively. Furthermore, all of the (R)-configured acyclic nucleoside derivatives displayed more potent anticancer activity compared to their (S)-counterparts. Mechanistic studies revealed that compound 9b triggered apoptosis in the cancer cell lines via depolarization of the mitochondrial membrane and effectively inhibited colony formation. Importantly, compound 9b inhibited the growth of the SW480 xenograft in a mouse model with low systemic toxicity. These results indicated that acyclic nucleoside compounds are viable as potent and effective anticancer agents, and compound 9b may serve as a promising lead compound that merits further attention in future anticancer drug discovery.

4,4'-Bipyridine-cyano-acetic acid (1/2).

Crystals of the title adduct, C(10)H(8)N(2)·2C(3)H(3)NO(2), were obtained from a methanol/water solution of cyano-acetic acid and 4,4'-bipyridine at room temperature. In the crystal structure, cyano-acetic acid and centrosymmetric 4,4'-bipyridine mol-ecules are linked by O-H⋯N hydrogen bonds to form three-component supra-molecular adducts. The acidic H atom is almost midway between the O and N atoms of the cyano-acetic acid and bipyridine mol-ecules, with O-H and N-H distances of 1.19 (3) and 1.39 (3) Å, respectively, so that the H-atom transfer is best regarded as partial. The three-component adducts are further inter-connected with neighboring mol-ecules by weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonds and by π-π stacking inter-actions [centroid-centroid distance = 3.7200 (11) Å] to generate a three-dimensional supra-molecular structure.

1,3-Di-4-pyrid-ylpropane-2-hydroxy-benzene-1,4-dicarboxylic acid (1/2).

In the title compound, C(13)H(14)N(2)·2C(8)H(6)O(5), which crystallized in the monoclinic C2/c space group, the 1,3-bis-(4-pyrid-yl)propane mol-ecules and 2-hydr-oxy-1,4-benzene-dicarboxylic acid mol-ecules are alternately linked by O-H⋯N and O-H⋯O hydrogen bonds into herringbone/zigzag chains.

[Studied on the determination of protein by probe of zinc 5-aminosalicylate].

Zinc 5- aminosalylicylate (5-ASZ), a new creative medicine, can react with serum albumin to form a complex. Based on this, a new method for the determination of proteins by synchronous fluorescence spectra under simulated physiological conditions was established using 5 - ASZ as a fluorescence probe. The spectral characterization and intensity of synchronous fluorescence were related to the value of deltalambda, reaction medium and reaction temperature, and so on. On basis of these, eperimental results show that, under the optimum conditions, the synchronous fluorescence intensity of the system is in proportion to the concentration of protein in the range of 1.66-496.8 microg x mL(-1) for human serum albumin (HSA). The detection limit was 0.88 microg x mL(-1) (n = 11) for HSA. On basis of these it had been applied to the determination of proteins in human serum, urine and spit samples with satisfactory results, the recovery was within the range of 98.0%-103.8%. Results suggested that the method possessed easy of implementation, rapidity, high sensitivity, broad linear range, and better RSD and recovery, and so on, and the method was employed directly to determine the total proteins in samples, which results were satisfactory.

A straightforward entry to chiral carbocyclic nucleoside analogues via the enantioselective [3+2] cycloaddition of α-nucleobase substituted acrylates.

A straightforward entry to chiral carbocyclic nucleoside analogues has been realized via the enantioselective [3+2] cycloaddition of α-nucleobase substituted acrylates to vinyl cyclopropanes for the first time. With Pd2(dba)3-L5 as the catalyst, carbocyclic purine, uracil, and thymine nucleoside analogues with quaternary stereocenters were obtained in excellent yields (up to 99% yield) and good enantioselectivities (up to 92% ee).