An efficient de novo synthesis of vineomycinone B2 methyl ester has been achieved. The longest linear route required only 14 steps from achiral commercially available starting materials (4.0% overall yield). The key transformations included the de novo asymmetric synthesis of two key fragments, which were joined by a convergent late stage Suzuki's glycosylation for the construction of the aryl ...

The biaryl structural motif is a predominant feature in many pharmaceutically relevant and biologically active compounds. As a result, for over a century1 organic chemists have sought to develop new and more efficient aryl-aryl bond-forming methods. Although there exist a variety of routes for the construction of aryl-aryl bonds, arguably the most common method is through the use of transition-...

Ceramides containing either sphingosine or sphinganine and one of the 2-hydroxy acids, 14h:0, 16h:0, 18h:0, 20h:0, 22h:0, 24h:0, and 26h:0 were prepared and separated by gas chromatography as the 1,3,2'-tri-O-tri-methylsilyl derivatives. Mass spectrometric analyses of these derivatives showed that the ions formed on electron impact can be used to determine unequivocally the structures of the lo...

The pyridyl and aryl rings in the title compound, C(16)H(15)NO(3)·H(2)O, which are located at the ends of the propenone unit, are nearly coplanar with this unit [dihedral angles = 3.74 (14) and 5.06 (13)°, respectively]; the rings are inclined at an angle of 6.2 (1)° with respect to each other. The solvent water mol-ecule forms hydrogen bonds with the pyridyl N atom and also with a symmetry-rel...

The title compound, C(14)H(15)BrN(2)O(2), an inter-mediate in drug discovery, was synthesized by the reaction of 5-bromo-pyridin-2-amine and 3,4-dimeth-oxy-benzaldehyde. In the crystal, molecules are linked via pairs ofN-H⋯N hydrogen bonds, leading to the formation of inversion dimers. A short contact occurs between the aryl H atom (ortho position from N) and the centroid of the benzene ring.

Symmetrical and asymmetrical cyclopropenones with diferrocenyl, diaryl and aryl-ferrocenyl substituents were obtained and their chemical behavior was studied. 1-Ethoxy-2,3-diarylcyclopropenylium terafluoroborate selectively reacts with MeLi, n-BuLi with formation of the 3,3-dialkyl-1,2-diarylcyclopropenes. The structures of 2,3-bis(4methoxyphenyl) cyclopropenone (10), 2-ferrocenyl-3-(4-methoxyp...

nano-graphene oxide was synthesized by the oxidation of graphite powders. the structural nature of the nano-graphene oxide was characterized by a variety of techniques including xrd, tem, ft-ir and uv/vis. the functional groups on its basal planes and edges of nano-grahene oxide play important role in catalytic activity. the catalytic activity of nano-graphene oxide was investigated on crossed-...

Natural nucleotides are not useful as fluorescent probes because of their low quantum yields. Therefore, a common methodology for the detection of RNA and DNA is the application of extrinsic fluorescent dyes coupled to bases in oligonucleotides. To overcome the many limitations from which fluorescent nucleotide-dye conjugates suffer, we have developed novel purine nucleosides with intrinsic flu...

Palladium-catalyzed cross-coupling reactions of alpha-aryl-beta,beta-difluoroenol silyl and alpha-aryl-beta-fluoroenol silyl ethers with aryl bromides proceed smoothly with good functional compatibility.