Visible-Light/Nickel-Catalyzed Carboxylation of C(sp) Bromides via Formate Activation.

A new visible-light-driven method for the carboxylation of (hetero)aryl/vinyl bromides has been developed using catalytic 4CzIPN, nickel, phenyl triflimide, and sodium formate as a carboxylation agent. Interestingly, we found catalytic phenyl triflimide plays an essential role in promoting the reaction. While many C(sp) carboxylation reactions require harsh reagents or gaseous carbon dioxide, we demonstrate the mild and facile construction of carboxylic acids from readily available starting materials.

Evaluation of 3,3'-Triazolyl Biisoquinoline ,'-Dioxide Catalysts for Asymmetric Hydrosilylation of Hydrazones with Trichlorosilane.

A new class of axial-chiral biisoquinoline ,'-dioxides was evaluated as catalysts for the enantioselective hydrosilylation of acyl hydrazones with trichlorosilane. While these catalysts provided poor to moderate reactivity and enantioselectivity, this study represents the first example of the organocatalytic asymmetric reduction of acyl hydrazones. In addition, the structures and energies of two possible diastereomeric catalyst-trichlorosilane complexes (-HSiCl) were analyzed using density functional theory calculations.