Synergistic Copper-Aminocatalysis for Direct Tertiary α-Alkylation of Ketones with Electron-Deficient Alkanes.

In this study, a novel approach for the tertiary α-alkylation of ketones using alkanes with electron-deficient C─H bonds is presented, employing a synergistic catalytic system combining inexpensive copper salts with aminocatalysis. This methodology addresses the limitations of traditional alkylation methods, such as the need for strong metallic bases, regioselectivity issues, and the risk of over alkylation, by providing a high reactivity and chemoselectivity without the necessity for pre-functionalized substrates. The dual catalytic strategy enables the direct functionalization of C(sp3)─H bonds, demonstrating remarkable selectivity in the presence of conventional C(sp3)─H bonds that are adjacent to heteroatoms or π systems, which are typically susceptible to single-electron transfer processes. The findings contribute to the advancement of alkylation techniques, offering a practical and efficient route for the construction of C(sp3)─C(sp3) bonds, and paving the way for further developments in the synthesis of complex organic molecules.

Enhanced hydrogen evolution activity of CsPbBr3 nanocrystals achieved by dimensionality change.

Dimensionality plays a vital role at the nanoscale in tuning the electronical and photophysical properties and surface features of perovskite nanocrystals. Here, 3D and 1D all-inorganic CsPbBr3 nanocrystals were chosen as model materials to systemically reveal the dimensionality-dependent effect in photocatalytic H2 evolution. In terms of facilitating photoinduced electron-hole pair separation and charge transfer, as well as inducing proton reduction potential with the presence of fewer Br vacancies, 1D CsPbBr3 nanorods gave about a 5-fold improvement for solar H2 evolution.

Switchable In Situ SO2 Capture and CF3 Migration of Enol Triflates with Peroxyl Compounds under Iron Catalysis.

Switchable in situ SO2 capture and CF3 migration of enol triflates with peroxyl compounds under iron catalysis are presented. By regulating the structure of peroxides, a variety of keto-functionalized dialkyl sulfones and α-trifluoromethyl ketones were selectively synthesized in good yields under mild conditions.

Copper-Catalyzed Cross-Nucleophile Coupling of ß-Allenyl Silanes with Tertiary C-H Bonds: A Radical Approach to Branched 1,3-Dienes.

Described herein is a distinctive approach to branched 1,3-dienes through oxidative coupling of two nucleophilic substrates, ß-allenyl silanes, and hydrocarbons appending latent functionality by copper catalysis. Notably, C(sp3)-H dienylation proceeded in a regiospecific manner, even in the presence of competitive C-H bonds that are capable of occurring hydrogen atom transfer process, such as those located at benzylic and other tertiary sites, or adjacent to an oxygen atom. Control experiments support the intermediacy of functionalized alkyl radicals.

Merging alkenyl C-H activation with the ring-opening of 1,2-oxazetidines: ruthenium-catalyzed aminomethylation of enamides.

1,2-Oxazetidines have been utilized as formaldimine precursors for the direct aminomethylation of enamides under a Ru(ii) species. By merging alkenyl C-H activation with ring-opening of 1,2-oxazetidines, this efficient protocol provides a facile and novel approach to synthesize Z-selective aminomethyl substituted enamides. Furthermore, two exemplified synthetic elaborations highlight the potential of this transformation.

Site-selective C(sp3)-H amination of thioamide with anthranils under Cp*CoIII catalysis.

Synthetically versatile anthranils as a bifunctional amino source have been employed for the first time to enable direct amination on unactivated C(sp3)-H bonds of thioamides under Cp*CoIII catalysis. The excellent site-selectivity on primary C(sp3)-H bonds is observed for a diverse array of thioamides with high functional group tolerance. Further applicability of the products is also highlighted through a series of interesting synthetic elaborations.