Oxidatively induced reactivity in Rh(iii)-catalyzed 7-azaindole synthesis: insights into the role of the silver additive.

A typical synthetic protocol for preparing 7-azaindoles involves the coupling of 2-aminopyridine and alkyne substrates using a Rh(iii)-catalyst. The catalysis requires the assistance of an external Ag oxidant that is thought to regenerate the catalyst and increase the turnover efficiency. Density functional theory (DFT) simulations confirm that Ag can oxidize various neutral Rh(iii) intermediates encountered at different stages of the catalysis.

Controlled Regulation of the Nitrile Activation of a Peroxocobalt(III) Complex with Redox-Inactive Lewis Acidic Metals.

Redox-inactive metal ions play vital roles in biological O activation and oxidation reactions of various substrates. Recently, we showed a distinct reactivity of a peroxocobalt(III) complex bearing a tetradentate macrocyclic ligand, [Co(TBDAP)(O)] () (TBDAP = ,'-di--butyl-2,11-diaza[3.3](2,6)pyridinophane), toward nitriles that afforded a series of hydroximatocobalt(III) complexes, [Co(TBDAP)(R-C(═NO)O)] (R = Me (), Et, and Ph).

Ligand-Controlled Product Selectivity in Electrochemical Carbon Dioxide Reduction Using Manganese Bipyridine Catalysts.

Electrocatalysis is a promising tool for utilizing carbon dioxide as a feedstock in the chemical industry. However, controlling the selectivity for different CO reduction products remains a major challenge. We report a series of manganese carbonyl complexes with elaborated bipyridine or phenanthroline ligands that can reduce CO to either formic acid, if the ligand structure contains strategically positioned tertiary amines, or CO, if the amine groups are absent in the ligand or are placed far from the metal center.

Peroxocobalt(iii) species activates nitriles via a superoxocobalt(ii) diradical state.

The dioxygenation of nitriles by [CoIII(TBDAP)(O2)]+ (TBDAP = N,N-di-tert-butyl-2,11-diaza[3.3](2,6)-pyridinophane) is investigated using DFT-calculations. The mechanism proposed previously based on experimental observations, which invoked an outer-sphere cycloaddition, was found to be unreasonable.

Brønsted acid catalysis of photosensitized cycloadditions.

Catalysis is central to contemporary synthetic chemistry. There has been a recent recognition that the rates of photochemical reactions can be profoundly impacted by the use of Lewis acid catalysts and co-catalysts. Herein, we show that Brønsted acids can also modulate the reactivity of excited-state organic reactions.

Site-Selective 1,1-Difunctionalization of Unactivated Alkenes Enabled by Cationic Palladium Catalysis.

A palladium(II)-catalyzed 1,1-difunctionalization of unactivated terminal and internal alkenes via addition of two nucleophiles was developed using a cationic palladium(II) complex. The palladacycle generated in situ as a result of a regioselective addition of a nucleophile to the alkene can readily undergo regioselective β-hydride elimination and migratory insertion with a cationic palladium catalyst. The resulting η-π-allyl palladium(II) complex is the key intermediate that reacts with a second nucleophile to furnish the desired 1,1-difunctionalization of the alkene.

Discovery of novel leucyladenylate sulfamate surrogates as leucyl-tRNA synthetase (LRS)-targeted mammalian target of rapamycin complex 1 (mTORC1) inhibitors.

According to recent studies, leucyl-tRNA synthetase (LRS) acts as a leucine sensor and modulates the activation of the mammalian target of rapamycin complex 1 (mTORC1) activation. Because overactive mTORC1 is associated with several diseases, including colon cancer, LRS-targeted mTORC1 inhibitors represent a potential option for anti-cancer therapy. In this work, we developed a series of simplified leucyladenylate sulfamate analogues that contain the N-(3-chloro-4-fluorophenyl)quinazolin-4-amine moiety to replace the adenine group.