Synthesis of β-Ketonitriles via -Heterocyclic-Carbene-Catalyzed Radical Coupling of Aldehydes and Azobis(isobutyronitrile).

Herein, an NHC (-heterocyclic carbene)-catalyzed radical coupling reaction between aldehydes and azobis(isobutyronitrile) (AIBN) has been developed. This method provides an efficient and convenient approach for the synthesis of β-ketonitriles containing a quaternary carbon center (31 examples, up to >99% yield) utilizing commercially available substrates. This protocol features broad substrate scope, good functional group tolerance, and high efficiency under metal-free and mild reaction conditions.

Stereoselective synthesis of C3-tetrasubstituted oxindoles copper catalyzed asymmetric propargylation.

Herein, a copper catalyzed asymmetric propargylation of 2-oxindole-3-carboxylate esters with terminal propargylic esters is described. This strategy successfully provides a direct approach to constructing a broad range of chiral C3-tetrasubstituted oxindoles with contiguous tertiary and quaternary carbon stereocenters in high yields and excellent enantioselectivities (16 examples, up to 99% yield and 98% ee). Moreover, the diastereoisomers of the two newly formed stereocenters can be separated by silica gel chromatography, thereby providing a valuable stereoselective access to all four possible stereoisomers of C3-tetrasubstituted oxindoles.

Copper-Catalyzed Bisannulations of Malonate-Tethered -Acyl Oximes with Pyridine, Pyrazine, Pyridazine, and Quinoline Derivatives for the Construction of Dihydroindolizine-Fused Pyrrolidinones and Analogues.

A copper-catalyzed bisannulation reaction of malonate-tethered -acyl oximes with pyridine, pyrazine, pyridazine, and quinoline derivatives has been developed for the concise synthesis of structurally novel dihydroindolizine-fused pyrrolidinones and their analogues. The present reaction shows excellent regioselectivity and stereoselectivity. Theoretical calculations reveal that the coordination effect of the carbonyl group in the nucleophilic substrate determines the excellent regioselectivity.

A Microchip Electrophoresis Device Integrated with the Top-bottom Antiparallel Electrodes of Indium Tin Oxide to Detect Inorganic Ions by Contact Conductivity.

A microchip electrophoresis (ME) device with off-channel contact conductivity detection (CD) was constructed using top-bottom antiparallel indium tin oxide (ITO) electrodes and a cross-type microchannel. The 500-m wide top-bottom antiparallel decouplers were found to effectively decrease the interference of the electrophoretic current. The cross-type microchannel was formed by bonding the patterned negative photoresist microstructures and the two top-bottom opposed ITO-deposited glass substrates.

Metal-free [3 + 2 + 1]/[2 + 2 + 1] biscyclization: stereospecific construction with concomitant functionalization of indolizin-5(1H)-one.

A metal-free [3 + 2 + 1]/[2 + 2 + 1] biscyclization strategy has been developed for the stereospecific construction with concomitant derivation of biologically significant indolizin-5(1H)-ones from simple and commercial starting materials. The transformations are notable because they can yield five new σ bonds and six stereocenters including a quaternary carbon center in a single operation.

Combinatorial synthesis of pyrazoloquinoline and pyrazoloacridine derivatives with high regioselectivity.

Three-component reaction of aldehyde, 1H-indazol-6-amine and 1,3-dicarbonyl compounds in EtOH under catalyst-free conditions, generates the corresponding pyrazolo[3,4-a]acridine, cyclopenta[b]pyrazolo[3,4-f]quinoline, indeno[1,2-b]pyrazolo[3,4-f]quinoline and benzo[h]pyrazolo[3,4-a]acridine derivatives in high yields and regioselectivity, respectively. The dicarbonyl compounds include 5,5-dimethylcyclohexane-1,3-dione, cyclopentane-1,3-dione, 2H-indene- 1,3-dione and 2-hydroxynaphthalene-1,4-dione.

A one-pot multicomponent strategy for stereospecific construction of tricyclic pyrrolo[1,2-a]quinolines.

A novel multicomponent strategy for the efficient synthesis of tricyclic pyrrolo[1,2-a]quinolines has been described. The bond-forming efficiency, accessibility and generality of this synthesis make it highly attractive to assemble tri-heterocyclic scaffolds.

Diaqua-bis-[5-(1-oxidopyridin-1-ium-2-yl)-1,2,3,4-tetrazolido]manganese(II) di-hydrate.

In the title compound, [Mn(C(6)H(4)N(5)O)(2)(H(2)O)(2)]·2H(2)O, the Mn(II) ion is situated on an inversion centre and is coordinated by the O and N atoms of two bis-chelating 5-(2-pyridyl-1-oxide)tetra-zolate ligands and two O atoms of two water mol-ecules in a distorted octa-hedral geometry. All the water H atoms are involved in O-H⋯N and O-H⋯O hydrogen bonds with uncoordinated water O atoms and tetra-zole N atoms, which link the mol-ecules into a three-dimensional network.

One-pot combinatorial synthesis of 4-aryl-1H-thiopyrano[3,4-b]pyridine-5-one derivatives.

A simple and efficient method for the combinatorial synthesis of highly substituted thiopyrano[3,4-b]pyridin-5(4H)-one, thiopyrano[3,4-b]quinoline-4,6(3H,5H)-dione, dithiopyrano[3,4-b:4',3'-e]pyridine-4,6(1H,3H)-dione, and pyrazolo[3,4-b]thiopyrano[4,3-e]pyridin-5(1H)-one derivatives has been developed. The synthesis was achieved via one-pot multicomponent reaction of aromatic aldehyde, 2H-thiopyran-3,5(4H,6H)-dione and enamine (such as the derivatives of amine and 1,3-dicarbonyl compounds and 3-methyl-1-phenyl-1H-pyrazol-5-amine) in glacial acetic acid. This procedure features short reaction time, generally good to excellent yields, easily available starting materials, and operational simplicity.

5'-Amino-2-oxo-2',3'-dihydro-spiro-[indoline-3,7'-thieno[3,2-b]pyran]-6'-carbonitrile 1',1'-dioxide.

In the title compound, C(15)H(11)N(3)O(4)S, the dihedral angle between the mean planes of the dihydro-indol-2-one (r.m.s.

Ethyl 7-(4-bromo-phen-yl)-5-trifluoro-methyl-4,7-dihydro-tetra-zolo[1,5-a]pyrimidine-6-carboxyl-ate.

In the title compound, C(14)H(11)BrF(3)N(5)O(2), the pyrimidine ring adopts a flattened envelope conformation with sp(3)-hybridized carbon as the flap [deviation = 0.177 (3) Å]. The dihedral angle between tetra-zole and bromo-phenyl rings is 84.

Ethyl 7-(2-chloro-phen-yl)-5-trifluoro-meth-yl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxyl-ate.

In the title compound, C(15)H(12)ClF(3)N(4)O(2), the dihydro-pyrimidine ring exhibits an envelope conformation. The dihedral angle between the mean planes of the dihydro-pyrimidine and phenyl rings is 83.94 (6)°.

5-Amino-7-(3-chloro-phen-yl)-3,7-di-hydro-2H-thieno[3,2-b]pyran-6-carbo-nitrile 1,1-dioxide.

The title compound, C(14)H(11)ClN(2)O(3)S, with fused thiophene and pyran rings, was synthesized via the condensation of dihydro-thio-phen-3(2H)-one 1,1-dioxide and 2-(3-chloro-benz-yl-idene)malononitrile catalysed by triethyl-amine in ethanol. The thio-phene ring adopts an envelope conformation and the pyran ring is planar (r.m.

5-Amino-7-(4-bromo-phen-yl)-3,7-di-hydro-2H-thieno[3,2-b]pyran-6-carbo-nitrile 1,1-dioxide.

In the title compound, C(14)H(11)BrN(2)O(3)S, the 2,3-dihydro-thio-phene ring is almost planar [maximum deviation = 0.006 (1) Å]. The pyran ring is in an envelope conformation [puckering parameters Q = 0.

Ethyl 2-amino-4-(3-chloro-phen-yl)-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carboxyl-ate.

The title mol-ecule, C(22)H(16)ClNO(5), was obtained by the reaction of (E)-ethyl 3-(3-chloro-phen-yl)-2-cyano-acrylate and 2-hydroxy-naphthalene-1,4-dione catalysed by triethylamine in ethanol. In the crystal structure, the chlorobenzene ring makes a dihedral angle of 88.63 (4)° with the fused ring system.

5-Benzoyl-4-hydr-oxy-6-(4-nitro-phen-yl)-4-trifluoro-meth-yl-3,4,5,6-tetrahydro-pyrimidin-2(1H)-one monohydrate.

The asymmetric unit of the title compound, C(18)H(14)F(3)N(3)O(5)·H(2)O, contains two independent formula units. The two heterocyclic mol-ecules differ in the orientations of the benzoyl-phenyl group with respect to the tetra-hydro-pyrimidine ring [C-C-C-C torsion angles of 64.5 (3) and 67.

Ethyl 4-(4-nitro-phen-yl)-2-(trifluoro-meth-yl)pyrimido[1,2-a]benzimidazole-3-carboxyl-ate.

In the title compound, C(20)H(13)F(3)N(4)O(4), the fused pyrimido[1,2-a]benzimidazole ring system is nearly planar, with a maximum deviation from the mean plane of 0.126 (1) Å. Mol-ecules are linked by C-H⋯N and C-H⋯O hydrogen bonds and by π-π inter-actions with inter-planar distances of 3.

2-Amino-1H-benzoimidazol-3-ium 4,4,4-trifluoro-1,3-dioxo-1-phenyl-butan-2-ide.

In the title compound, C(7)H(8)N(3) (+)·C(10)H(6)F(3)O(2) (-), 1H-benzoimidazol-2-amine system adopts a planar conformation with an r.m.s.

4-Phenyl-1,2,3,4-tetra-hydro-pyrimido[1,2-a]benzimidazol-2-one.

In the title compound, C(16)H(13)N(3)O, the tetrahydropyrimidin-one ring adopts a sofa conformation. In the crystal structure, mol-ecules are linked by N-H⋯N hydrogen bonds and C-H⋯π inter-actions.

3-Ethyl 5-methyl 2-hydr-oxy-6-methyl-4-(4-nitro-phen-yl)-2-trifluoro-methyl-1,2,3,4-tetra-hydro-pyridine-3,5-dicarboxyl-ate.

In the title compound, C(18)H(19)F(3)N(2)O(7), the tetrahydropyridine ring adopts a half-chair conformation. The nitro group is disordered over two sites with occupancies of 0.780 (15) and 0.

The synthesis and herbicidal activity of 1-alkyl-3-(alpha-hydroxy-substituted benzylidene)pyrrolidine-2,4-diones.

In the search for better herbicides a series of 1-alkyl-3-(alpha-hydroxy-(un)substituted benzylidene)pyrrolidine-2,4-diones were prepared and their structure-activity relationships studied. All their structures have been confirmed by (1)H-NMR and elemental analysis. The preliminary bioassay results indicated that some of them have high herbicidal activity against annual dicotyledonous and monocotyledonous plants.

Efficient and direct synthesis of poly-substituted indeno[1,2-b]quinolines assisted by p-toluene sulfonic acid using high-temperature water and microwave heating via one-pot, three-component reaction.

Reactions of aldehydes, 1,3-indanedione and enaminones were successfully carried out using p-toluene sulfonic acid (p-TsOH) as a catalyst and high-temperature water as a solvent under microwave irradiation. This method provided several advantages such as rapid reaction times, high yields, and a simple workup procedure. In addition, a possible mechanism to account for the reaction was proposed.

An efficient one-pot, three-component synthesis of indeno[1,2-b]quinoline-9,11(6H,10H)-dione, acridine-1,8(2H,5H)-dione and quinoline-3-carbonitrile derivatives from enaminones.

An efficient one-pot, three-component method for the preparation of indeno[1,2-b]quinoline-9,11(6H,10H)-dione, acridine-1,8(2H,5H)-dione and various multi-substituted quinoline-3-carbonitrile derivatives has been developed through the Michael addition to enaminones, which was achieved by both microwave irradiation and conventional heating.