Highly controlling selectivity of copper(I)-catalyzed azide/alkyne cycloaddition (CuAAC) between sulfonyl azids and normal alkynes or propynoates

• Published in: Tetrahedron Vol. 67; no. 34; pp. 6294 - 6299
• Main Authors: Liu, Yantao, Wang, Xinyan, Xu, Jimin, Zhang, Qun, Zhao, Yi, Hu, Yuefei
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 26.08.2011; Elsevier
• Subjects: 2-Aminophenol; Alkynes; Azide/alkyne cycloaddition; Catalysis; CATALYSTS; Catalysts: preparations and properties; Chains; Chemistry; Chemistry, Organic; COMPUTERIZED PROCESS CONTROLS; Control systems; COPPER OXIDE; Copper(I) catalyst; Copper(II) acetate; Exact sciences and technology; General and physical chemistry; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; LIGANDS; Organic chemistry; Physical Sciences; Preparations and properties; Protonation; Science & Technology; Sulfonyl azids; Tetrahedrons; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Sulfonyl azids; Azide/alkyne cycloaddition; Copper(II) acetate; 2-Aminophenol; Copper(I) catalyst; CATALYZED MULTICOMPONENT REACTION; ROOM-TEMPERATURE; ONE-POT SYNTHESIS; AMIDE SYNTHESIS; EFFICIENT SYNTHESIS; TERMINAL ALKYNES; SYNTHETIC UTILITY; FACILE ACCESS; N-SULFONYLAMIDINES; WATER; Water; Catalytic reaction; Chemical reagent; Acetylenic compound; Sulfone; Organic azide; Ligand; Selectivity; Copper II Acetate; Experimental study; Aminophenols; Azides; Cycloaddition; Copper ion; Copper I; Protonation; Catalyst; Alkyne
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2011.06.017

In this article, a combination of Cu(OAc) 2·H 2O/2-aminophenol was developed as a highly efficient and controlling catalytic system for sulfonyl azids involved CuAAC. By using this catalytic system, sulfonyl azids reacted with normal alkynes or propynoates to selectively give the ring products or the chain products, respectively, in excellent yields within minutes. HOAc in situ produced in the reaction has been proved to be a super protonation reagent, by which the unstable intermediate 5-cuprated 1,2,3-triazole was protonated efficiently to yield ring-product 1-sulfonyl 1,2,3-trizoles. The control experiments also proved that 2-aminophenol played dual roles as both ligand and reductant, which led to the cheap and chemically stable Cu(OAc) 2·H 2O being an efficient copper source for our purpose. [Display omitted]