Synthesis of Helical-Shaped Axially Chiral Bisoxime Ethers via Chiral Phosphoric-Acid-Catalyzed Sequential Enantioselective Condensations.

A successful synthesis of helical-shaped axially chiral bisoxime ethers is reported. This approach utilized symmetric L-shaped diketone scaffolds as carbonyl components for the enantioselective condensation with hydroxylamines, delivering dual axially chiral oxime ethers with up to 99% ee. Additionally, the axially chiral mono-oxime ethers of azabicyclic ketones with high ee's were also successfully produced.

Visible-Light-Promoted Radical Cross-Dehydrogenative Coupling of C(sp)-H/C(sp)-H and C(sp)-H/C(sp)-H via Intermolecular HAT.

Cross-dehydrogenative coupling has emerged as a robust tool to construct C-C and C-heteroatom bonds. Herein, we reported an interesting visible-light-mediated radical CDC of C(sp)-H/C(sp)-H and C(sp)-H/C(sp)-H, enabled by a phenyl radical guided intermolecular HAT process. This strategy allowed the efficient coupling of a wide range of inert C(sp)-H and C(sp)-H with α-N C(sp)-H of amines in good regioselectivities and yields.

Asymmetric hydrogenation of O-/N-functional group substituted arenes.

Asymmetric hydrogenation of aromatic compounds represents one of the most straightforward synthetic methods to construct important chiral cyclic skeletons that are often found in biologically active agents and natural products. So far, the most successful examples in this field are largely limited to aromatics containing alkyl and aryl substituted groups due to the poor functional-group tolerance of hydrogenation. Direct asymmetric hydrogenation of functionalized aromatics provides enormous potential for expanding the structural diversity of reductive products of planar aromatic compounds, which is highly desirable and has not been well studied.

The Photocatalyst-Free Cross-Dehydrogenative Coupling Reaction Enabled by Visible-Light Direct Excitation of Substrate.

A new photocatalyst-free strategy for the cross-dehydrogenative C-C and C-P coupling reaction has been described. This protocol provides a concise method to synthesize various 1-substituted tetrahydroisoquinoline (THIQ) derivatives enabled by visible-light direct excitation of substrates without using any photocatalyst. Moreover, a wide substrate scope demonstrated good synthetic versatility and practicality.