Study on the coordination conduct and kinetic insights within the oxo-vanadate and organic reductive nitrogen and sulfur functionalities during the reduction coupled adsorption processes: Implications in practical applications.

Vanadium(V) is arising wastewater contaminant recently. Although bio-reduction of vanadium(V) is effective, the knowledge of electron transfer pathways and coordination nature by cellular organic functionalities is seriously lacking. Herein, the coordination conduct and kinetic modes for the reduction of V(V) by organic nitrogen and sulfur functionalities in working pHs are comprehensively investigated for the first time.

Observing the Agostic Hydrogen in Pd(II)-Catalyzed Aromatic C-H Activation.

Direct C-H activation and functionalization offer a convenient protocol for pharmaceutical and material syntheses. Although versatile mechanisms have been proposed to depict transition-metal-catalyzed C-H activation, to date, the shared key agostic hydrogen intermediate in several major mechanisms has not been observed yet, which apparently puzzles the mechanism-based catalyst design. This work reports the direct observations of this intermediate in Pd(II)/Sc(III)-catalyzed C-H activation of acetanilides, and its stability and reactivity in C-H activation are investigated.

Pd(II)/Lewis Acid Catalyzed Intramolecular Annulation of Indolecarboxamides with Dioxygen through Dual C-H Activation.

Transition-metal ion catalyzed intramolecular dual C-H activation to construct polycyclic heteroarene skeletons is merited for its step and atom-economic advantages in organic synthesis. However, in most cases, stoichiometric oxidants, elevated temperature, and other harsh conditions were commonly faced for this reaction, which apparently block the synthetic applications. Herein, we report a Pd(II)/LA (LA: Lewis acid) catalyzed intramolecular dual C-H activation to construct indoloquinolinone derivatives under mild conditions with dioxygen as the sole oxidant.

Palladium(II)/Lewis Acid-Catalyzed Olefination of Arylacetamides with Dioxygen.

The present work introduces Pd(II)/LA-catalyzed (LA: Lewis acid) olefination of arylacetamides with dioxygen as the oxidant source. This protocol tolerates with different functional groups on the substrates, and the catalytic efficiency is highly Lewis acidity-dependent on added LA, that is, a stronger LA provided a better promotional effect. The H NMR studies of the semireaction between the arylacetamide and the Pd(II)/Sc(III) catalyst in HOAc- disclosed the formation of a palladacycle intermediate, and the C-H activation step was reversible, which led to the formation of the deuterated arylacetamide substrate and the palladacycle intermediate.

Pd(II)/Lewis acid catalyzed regioselective olefination of indole with dioxygen.

Transition metal ion catalyzed indole olefination through C-H activation is a convenient protocol to synthesize versatile bioactive vinylindole compounds; however, in most cases, stoichiometric amounts of oxidants were necessary to accomplish the catalytic cycle. The present study describes a Pd(II)/LA (LA: Lewis acid) catalyzed indole olefination with dioxygen as the sole oxidant. The olefination reaction with electron-rich olefins proceeded smoothly through the pyrrolyl -carboxamide group directed remote C-H activation at the C3 position of the indole with the Pd(II)/LA catalyst, whereas Pd(II) alone was a very sluggish catalyst under identical conditions.

Decarboxylative Addition of Propiolic Acids with Indoles to Synthesize Bis(indolyl)methane Derivatives with a Pd(II)/LA Catalyst.

Exploring new protocols for efficient organic synthesis is crucial for pharmaceutical developments. The present work introduces a Pd(II)/LA-catalyzed (LA: Lewis acid) decarboxylative addition reaction for the synthesis of bis(indolyl)methane derivatives. The presence of Lewis acid such as Sc(OTf) triggered Pd(II)-catalyzed decarboxylative addition of propiolic acids with indoles to offer the bis(indolyl)methane derivatives in moderate to good yields, whereas neither Pd(II) nor Lewis acid alone was active for this synthesis.

Palladium(II)/Lewis Acid-Catalyzed Oxidative Olefination/Annulation of -Methoxybenzamides: Identifying the Active Intermediates through NMR Characterizations.

Although Pd(II)-catalyzed C-H activation in arenes has been widely successful in organic synthesis with many palladacycle compounds isolated as the intermediates in ligand-directed C-H activation, direct identification of the reaction intermediates such as the π-complex prior to the C-H activation is still not successful because of their instability. In the present study, we introduce a Pd(II)/LA (LA: Lewis acid)-catalyzed oxidative olefination/annulation reaction between -methoxybenzamides and acrylates with oxygen as the oxidant source, in which two intermediates, including an unsymmetrical η-complex and a palladacycle species without the proton releasing to the environment, were identified through NMR characterizations. The formation of the heterobimetallic Pd(II)/LA species such as Pd(II)/Sc(III) may have enhanced the electrophilic properties of the Pd cation, thus improving the stability of the π-complex, herein, an unsymmetrical η-complex, and improving its catalytic efficiency.

Characteristics of human papillomaviruses distribution in Guizhou Province, China.

Background: Human papillomavirus (HPV) is one of the most common sexually transmitted viruses. Data about HPV infection in Guizhou is limited.

Methods: 56,768 cervical samples were collected and genotyped for 15 main high risk and 6 main low risk HPV types.

Synthesis of N-Substituted Benzamide Derivatives and their Evaluation as Antitumor Agents.

Background: Histone deacetylases inhibitors (HDACIs) with different chemical structures have been reported to play an important role in the treatment of cancer.

Objective: The study aims to modify the structure of Entinostat (MS-275) to discover new compounds with improved anti-proliferative activities and perform SAR studies on this class of bioactive compounds.

Methods: Fourteen N-substituted benzamide derivatives were synthesized and their antiproliferative activities were tested with four cancer cell lines (MCF-7, A549, K562 and MDA-MB- 231) by MTT assay.