Related Experiment Video
Updated: Aug 7, 2025

Chemoselective Modification of Viral Surfaces via Bioorthogonal Click Chemistry
Published on: August 19, 2012
Sulfonyl-PYBOX Ligands Enable Kinetic Resolution of α-Tertiary Azides by CuAAC
Yi Gong1, Cai Wang1, Feng Zhou1
1Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China.
Abstract:
We report the first highly selective kinetic resolution of racemic α-chiral azides via Cu-catalyzed azide-alkyne cycloaddition (CuAAC). Newly developed pyridine-bisoxazoline (PYBOX) ligands, bearing a C4 sulfonyl group, enable effective kinetic resolution of racemic azides derived from privileged scaffolds such as indanone, cyclopentenone, and oxindole, and their asymmetric CuAAC to afford α-tertiary 1,2,3-triazoles with high to excellent ee values. DFT calculations and control experiments reveal that the C4 sulfonyl group decreases the Lewis basicity of the ligand and increases the electrophilicity of the copper center for better recognition of azides, and functions as a shielding group to make the chiral pocket of the catalyst more effective.
More Related Videos
Related Concept Videos
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Preparation and Reactions of Sulfides
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Acid Halides to Esters: Alcoholysis
Amines to Sulfonamides: The Hinsberg Test
Generally, a primary amine reacts with the Hinsberg reagent to produce an N-substituted benzenesulfonamide. The electron-withdrawing...
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions

