Lewis Acid Enables Ketone Phosphorylation to Form a C-P Bond and a C-C Bond: Synthesis of 9-Phosphoryl Fluorene Derivatives.

An efficient method for the Lewis acid promotion of the synthesis 9-phosphoryl fluorenes has been reported. This method focuses on ketone phosphonylation to form a C-P bond and a C-C bond between diphenylmethanone and H-phosphinate esters, H-phosphites, and H-phosphine oxides via phospha-aldol elimination, in which a series of 9-phosphoryl fluorene derivatives were selectively obtained in moderate to excellent yields.

Palladium-catalyzed oxidative cross-coupling for the synthesis of α-amino ketones.

A novel oxidative cross-coupling reaction for the synthesis of α-aryl α-amino ketones in the presence of palladium catalysts using T+BF4 - as an oxidant has been developed. This transformation was achieved by direct C-H oxidation of α-aminocarbonyl compounds and arylation. The mild reaction has a broad reaction scope and gives desired α-aryl α-amino ketones in moderate to excellent yields.

Using N-tosylhydrazone as a double nucleophile in the palladium-catalyzed cross-coupling reaction to synthesize allylic sulfones.

Without extra addition of sulfinate salt, allylic sulfones were synthesized by palladium-catalyzed cross-coupling of aryl iodide with N-tosylhydrazone. In this transformation, not only the diazo compound but also the sulfinate salt, which were both generated in situ from base-mediated decomposition of the N-tosylhydrazone, was used as nucleophilic partner.

[Effect of sand dust weather on major water-soluble ions in PM10 in Lanzhou, China].

The major water-soluble ions (Ca(2+), NH(4+), Mg(2+), K(+), Na(+), SO4(2-), NO3(-) and Cl-(-) in PM10 at 1-h interval were measured by an online analyzer for monitoring of Aerosols and Gases (MARGA) at the campus of Lanzhou University, from April 1 to June 30, 2011. There were 15 days of dust weather during the monitoring period. The main water-soluble ions in PM10 were Ca(2+), SO4(2-) and NO3(-). The concentration of NO3(-) and NH4(+) decreased during blowing sand weather comparing with non-dust, this phenomenon showed that the dust weather had the function of eliminating the local anthropogenic emissions. As the soil pollution marker, the concentration of Mg(2+), Na(+) and Ca(2+) increased during dust weather comparing with non-dust. The correlation coefficients between Na(+) and Mg(2+), Na(+) and Ca(2+), Mg(2+) and Ca(2+) during dust weather were 0.520, 0.659 and 0.671, respectively. The similar correlation coefficients indicated that some fraction of these species was derived from the same sources, such as soil dust. The correlation coefficients between Na(+) and Mg(2+), Na(+) and Ca(2+), Mg(2+) and Ca(2+) during non-dust weather were not strong, only 0.065, 0.131 and 0.163, respectively. The low correlation coefficients indicated that these species were derived from different sources. The mass concentration of Cl(-) in the dust weather was significantly higher than that of floating dust and non dust, indicating that soil dust was the main source of Cl(-).

Direct oxidative nitration of aromatic sulfonamides under mild conditions.

A direct nitration of aromatic sulfonamides using sodium nitrite as the nitrating agent has been developed. The reaction shows typically mono-substitution selectivity and can be enlarged to the gram scale with good yield.

Palladium-catalyzed insertion of N-tosylhydrazones for the synthesis of isoindolines.

Isoindolines are synthesized by palladium-catalyzed coupling reaction of N-(2-iodobenzyl) anilines with α,ß-unsaturated N-tosylhydrazones. The reaction has several potential advantages: (1) toleration of a wide range of functional groups, (2) easy to handle and with mild conditions, (3) enriches the isoindoline family, (4) two new bonds form in one step.

Palladium-catalyzed insertion of α-diazocarbonyl compounds for the synthesis of cyclic amino esters.

Two different cyclic amino esters are synthesized by palladium-catalyzed cross-coupling reaction of diazoesters with N-substituted-2-iodoanilines. Aryldiazoacetates lead to cyclic α-amino esters with an α-quaternary carbon centre in the presence of CO. Additionally, arylvinyldiazoacetates afford cyclic α,ß-unsaturated γ-amino esters.

Palladium-catalyzed synthesis of indene derivatives via propargylic carbonates with in situ generated organozinc compounds.

The palladium-catalyzed carboannulation and arylation reaction of propargylic carbonates with in situ generated organozinc compounds produced an important new class of indene derivatives. The reaction proceeded under mild conditions, and indene products were isolated in good to excellent yields.

Copper-catalyzed [4 + 1] cycloadditions of alpha,beta-acetylenic ketones with diazoacetates to form trisubstituted furans.

Copper-catalyzed [4 + 1] cycloaddition reaction of alpha,beta-acetylenic ketones with alpha-diazo esters offers an efficient, direct route to highly substituted furans. The reaction conditions and the scope of the process are examined, and a possible mechanism is proposed.