English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

An unprecedented CuBr-ZnI 2 combo-catalyzed mild Cu 1 -Cu III switching activation of sp 2 C-H of highly electron-rich arenes is reported. Anilines, aldehydes, and terminal alkynes were rapidly coupled together at ambient temperature to construct a ubiquitous quinoline framework through cyclization of the C≡C bond. This smart solvent-free strategy was exploited for the direct synthesis of valuable 4-substituted, 2,4-disubstituted, and thermally labile sugar-based chiral quinolines in good yields. In contrast to the frequently used imine-alkyne cyclization reaction, this uncommonly mild Cu I -Cu III combo-catalysis for a rapid three-component cyclization is expected to proceed through the formation of a flexible propargyl amine intermediate, which provides a Cu I -procatalyst for rapid sp 2 C-H activation with cyclization involving transient Cu III species. The in situ generation of transient Cu III species was confirmed through online ultraviolet-visible spectroscopy (UV-vis), electrospray ionization mass spectrometry (ESI-MS), and X-ray photoelectron spectroscopy (XPS) analyses.

acs omega

CuBr–ZnI2 Combo-Catalysis for Mild CuI–CuIII Switching and sp2 C–H Activated Rapid Cyclization to Quinolines and Their Sugar-Based Chiral Analogues: A UV–Vis and XPS Study