Huajiang Jiang

Improved Synthesis of 2,9-Dichloro-1,10-phenanthroline

1,10-Phenanthroline is a classic ligand that plays an important role in coordination chemistry and continues to be of considerable interest as a versatile starting material in organic, inorganic and supramolecular chemistry.1,2 As for 1,10-phenanthroline derivatives, most of the recent work has been prompted by the intense current interest in their molecular recognition, photophysical, catalysis, redox properties and cleavages of DNA.3–5 Thus, a simple and convenient access to 1,10-phenanthroline building blocks appears of importance. Surprisingly, the functionalization of the 2,9-positions of 1,10-phenanthroline ligand appears to be relatively rare. Among these derivatives, 2,9-dihalo-1,10-phenanthrolines are the most versatile starting materials of particular importance as they can be used either directly for metal-catalyzed cross-coupling reactions to form additional derivatives or for the preparation of the 2,9-diamino,6 2,9-dialkoxy7 and 2,9-diacetyl8 analogues. The synthesis of 2,9-dichloro-1,10-phenanthroline (4) has been reported by two groups. The conventional method (Route 1, Scheme 1) leads to 4 in six steps and in low overall yields (44%) from 1,10-phenanthroline (1).9,10 Compound 4 has also been obtained in a three-step sequence (Route 2, Scheme 2) from 1.11,12 Compound 2 was obtained in 88% yield by

N-Phenylpyridine-2-carb­amide

In the title compound, C12H10N2O, the dihedral angle between the pyridine ring system and the phenyl ring is 1.8 (1)°. There is an intramolecular N—H⋯N hydrogen bond between the pyridine N atom and the amide NH function.

Ruthenium-catalyzed decarboxylative C–S cross-coupling of carbonothioate: synthesis of allyl(aryl)sulfide

A novel ruthenium-catalyzed decarboxylative cross-coupling of carbonothioate is disclosed. This method provides straightforward access to the corresponding allyl(aryl)sulfide derivatives in generally good to excellent yields under mild conditions and features a broad substrate scope, wide group tolerance and in particular, no need to use halocarbon precursors.

An Additive-Free, Base-Catalyzed Protodesilylation of Organosilanes

We report an additive-free, base-catalyzed C-, N-, O-, and S-Si bond cleavage of various organosilanes in mild conditions. The novel catalyst system exhibits high efficiency and good functional group compatibility, providing the corresponding products in good to excellent yields with low catalyst loadings. Overall, this transition-metal-free process may offer a convenient and general alternative to current employing excess bases, strong acids, or metal-catalyzed systems for the protodesilylation of organosilanes.

Gold-catalyzed intermolecular oxidation of phenylacetylene and allylic sulfides: an efficient and practical synthesis of α -phenylthio ketone

An efficient and practical synthesis of α-phenylthio ketone through gold-catalyzed intermolecular oxidation of phenylacetylene and substituted aryl(benzyl) allylic sulfides was developed. The reaction scope is fairly good with substituted aryl(benzyl) allylic sulfides, tolerating various functional groups, and the reaction affords the yields of 63%—85%.

A general and mild Cu-catalytic N-arylation of iminodibenzyls and iminostilbenes using unactivated aryl halides

A ligand-free, highly efficient Cu-catalytic N-arylation of iminodibenzyl and iminostilbene derivatives with a broad scope of unactivated aryl halides under mild conditions has been developed for the first time. Moreover, the first Ni-based catalytic system was also applied to the N-arylation of pre-existing derivatives. These novel protocols provide facile and convenient access to the construction of dibenzazepines and offer promising alternatives to the widely used palladium catalysts.

3-Methyl-4-oxo-2-phenyl-4H-chromene-8-carboxylic acid.

In the title compound, C17H12O4, the chromene unit is approximately planar, the maximum deviation from the mean plane being 0.0166 Å. The attached phenyl ring makes a dihedral angle of 53.2 (1)° with the fused ring system. The packing of the molecules in the crystal structure is governed by C—H⋯O and O—H⋯O hydrogen-bonding interactions.