Synthesis, characterization, molecular docking, and anticancer activities of new 1,3,4-oxadiazole-5-fluorocytosine hybrid derivatives.

Analogs of pyrimidine and 1,3,4-oxadiazole are two well established class of molecules proven as potent antiviral and anticancer agents in the pharmaceutical industry. We envisioned designing new molecules where these two heterocycles were conjugated with the goal of enhancing biological activity. In this vein, we synthesized a series of novel pyrimidine-1,3,4-oxadiazole conjugated hybrid molecules as potential anticancer and antiviral agents.

Efficient production of few-layer black phosphorus by liquid-phase exfoliation.

Phosphorene is a new two-dimensional material that has recently attracted much attention owing to its fascinating electrical, optical, thermal and chemical properties. Here, we report on high-quality exfoliation of black phosphorus nanosheets, with controllable size produced in large quantities by liquid-phase exfoliation using -methyl-2-pyrrolidone (NMP) as a solvent under ambient conditions. The as-synthesized few layers show a great potential for solar energy conversion based on the optical results shown in this work.

Tip-induced oxidation of silicene nano-ribbons.

We report on the oxidation of self-assembled silicene nanoribbons grown on the Ag (110) surface using scanning tunneling microscopy and high-resolution photoemission spectroscopy. The results show that silicene nanoribbons present a strong resistance towards oxidation using molecular oxygen. This can be overcome by increasing the electric field in the STM tunnel junction above a threshold of +2.

Calcium trifluoroacetate as an efficient catalyst for ring-opening of epoxides by amines under solvent-free conditions.

Ca(CF3CO2)2 efficiently catalyzed the selective ring-opening of epoxides by amines leading to the synthesis of β-aminoalcohols. The reaction works well with various aromatic and aliphatic amines under solvent-free conditions. Corresponding β-aminoalcohols were obtained in excellent yields with high regioselectivity.

Silicon sheets by redox assisted chemical exfoliation.

In this paper, we report the direct chemical synthesis of silicon sheets in gram-scale quantities by chemical exfoliation of pre-processed calcium disilicide (CaSi2). We have used a combination of x-ray photoelectron spectroscopy, transmission electron microscopy and energy-dispersive x-ray spectroscopy to characterize the obtained silicon sheets. We found that the clean and crystalline silicon sheets show a two-dimensional hexagonal graphitic structure.

(2Z,2'Z)-Diethyl 3,3'-[butane-1,4-diylbis(aza-nedi-yl)]bis-(but-2-enoate).

The whole mol-ecule of the title β-enamino-ester, C(16)H(28)N(2)O(4), is generated by a crystallographic inversion center, situated at the mid-point of the central C-C bond of the 1,4-diamino-butane segment. There are two intra-molecular N-H⋯O hydrogen bonds that generate S(6) ring motifs. This leads to the Z conformation about the C=C bonds [1.

(R)-2-Methyl-5-[(R)-2,4,4,4-tetra-chloro-butan-2-yl]cyclo-hex-2-enone.

The title compound, C(11)H(14)Cl(4)O, was efficiently synthesized by atom-transfer radical addition between (R)-carvone and tetra-chloro-methane. In the mol-ecule, both chiral centres are of the absolute configuration R. The cyclo-hex-2-enone ring has an envelope conformation with the chiral C atom displaced by 0.

(5R)-5-[(1R)-2,2-Dichloro-1-methyl-cyclo-prop-yl]-2-methyl-cyclo-hex-2-en-1-one.

The title compound, C(11)H(14)Cl(2)O, was synthesized by the reaction of a dichloro-methane solution of (R)-carvone and potassium tert-butano-late in the presence of a catalytic amount of benzyl-triethyl-ammonium chloride in chloro-form. The cyclo-hexene ring adopts a half-boat conformation. The cyclo-propyl ring is unsymmetrical, the shortest C-C bond being distal to the alkyl-substituted C atom.

2-(Naphthalen-1-yl-amino)-cyclo-hexa-nol.

The title compound, C(16)H(19)NO, was synthesized under solvent-free conditions by reaction of 7-oxa-bicyclo-[4.1.0]heptane and naphthalen-1-amine in the presence of Ca(CF(3)COO)(2) as catalyst.

rac-Ethyl (2Z)-3-{2-[(Z)-4-eth-oxy-4-oxobut-2-en-2-yl-amino]-cyclo-hexyl-amino}-but-2-enoate.

The asymmetric unit of the title compound, C(18)H(30)N(2)O(4), contains two independent mol-ecules. In each mol-ecule, the cyclo-hexane ring adopts a chair conformation with equatorial orientation of the substituents, and the conformation is stabilized by two intra-molecular N-H⋯O hydrogen bonds, forming rings of S(6) graph-set motif. One eth-oxy group and one ethyl group are disordered over two sets of sites with refined occupancy ratios of 0.

(S)-4-(2-Chloro-propan-2-yl)-1-(2,2,2-trichloro-eth-yl)cyclo-hexene.

The title compound, C(11)H(16)Cl(4), was synthesized by the reaction of (1S)-β-pinene with triethyl-amine in the presence of ZnCl(2). The cyclo-hexene ring assumes a half-boat conformation. The crystal packing is governed only by van der Waals inter-actions.

Ni(0)-CMC-Na - nickel colloids in sodium carboxymethyl-cellulose: catalytic evaluation in hydrogenation reactions.

A recyclable catalyst, Ni(0)-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na), was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.

4-Chloro-N-methyl-2-(1,2,3,4-tetra-hydro-isoquinolin-1-yl)aniline.

The racemic title compound, C(16)H(17)ClN(2), shows a tetra-hydro-isoquinoline skeleton with a 4-chloro-N-methyl-aniline group linked to the C atom at position 1. The dihedral angle between the benzene rings is 85.82 (4)°.

[(1R,4S)-(+)-3-Benzoyl-1,7,7-trimethyl-bicyclo-[2.2.1]heptan-2-olato-κO,O](η-norbornadiene)rhodium(I).

In the title complex mol-ecule, [Rh(C(17)H(19)O(2))(C(7)H(8))], the rhodium(I) metal centre is coordinated by the O atoms of a benzoyl-camphorate anion and the C=C bonds of the norbornadiene mol-ecule into a slightly distorted square-planar coordination geometry. The six-membered chelate ring is essentially planar (r.m.

[(1R)-3-Benzoyl-1,7,7-trimethyl-bicyclo-[2.2.1]heptan-2-onato-κO,O']chlorido(η-p-cymene)ruthenium(II).

The asymmetric unit of the title compound, [RuCl(C(10)H(14))(C(17)H(19)O(2))], contains two diastereomers. In both, the Ru(II) ion has a tetra-hedral coordination, formed by two O atoms of the camphor-derived ligand and the p-cymene and Cl ligands. In the crystal structure, weak inter-molecular C-H⋯Cl inter-actions link the mol-ecules into columns propagated along [010].

(1S,2R,4S)-1-[(Benzyl-amino)-meth-yl]-4-(prop-1-en-2-yl)cyclo-hexane-1,2-diol.

The title compound, C(17)H(25)NO(2), was synthesized by epoxidation of the double bond of (S)-perillyl alcohol [(S)-4-isopropenyl-1-cyclo-hexenyl-methanol], followed by the oxirane ring-opening by benzyl-amine using [Ca(CF(3)CO(2))(2)] as catalyst under solvent-free condition at 313 K. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯N hydrogen bond. In the crystal, mol-ecules are linked by inter-molecular N-H⋯O hydrogen bonds, forming chains parallel to the a axis, which are further connected by O-H⋯O hydrogen bonds into sheets parallel to (010).

Distinct ribonucleoprotein reservoirs for microRNA and siRNA populations in C. elegans.

MicroRNAs (miRNAs) are regulatory molecules that share both biosynthetic derivation (cleavage from short hairpin precursor RNAs) and functional roles (downregulation of specific mRNAs through targeted degradation and/or translational inhibition). A distinct family of small RNAs, termed siRNAs, have some common characteristics but exhibit distinct modes of biosynthesis and function. In this study, we report procedures for purification of a predominant species of miRNA-containing ribonucleoprotein complexes from Caenorhabditis elegans and demonstrate that this population is distinct from the predominant pool of siRNA-containing ribonucleoprotein complexes.