Fluorinated Anions Promoted “on Water” Activity of Di- and Tetranuclear Copper(I) Catalysts for Functional Triazole Synthesis
摘要:
A set of di- and tetra-copper(I) compounds [Cu-2((LH)-H-1)(2)][BArF](2) (1) ((LH)-H-1 = bis(5,7-dimethyl-1,8-naphthyridin-2-yl)amine; BArF = [B{C6H3(CF3)(2)}(4)]) and [Cu-4(L-1)(2)(L-2)(2)][BNBF](2) (2) (L-2 = 5,7-dimethyl-1,8-naphthyridin-2-amine; BNBF = [NH2{B(C6F5)(3)}(2)]), stabilized by naphthyridine-based ligands and containing fluorinated anions, is synthesized. Their catalytic utility for copper(I)-catalyzed azidealkyne coupling (CuAAC) reactions in organic solvents and on water is evaluated. The dimer analogue [Cu-2((LH)-H-1)(2)][BPh4](2) (3) with nonfluorinated anion is synthesized for the purpose of comparison. All three compounds show CuAAC activity in organic solvents, although the performance of 3 is considerably lower. Remarkable rate enhancement is displayed by compounds containing fluorinated anions (1 and 2) under on water conditions for the model reaction involving benzyl azide, affording 98% conversions in 1520 min, where compound 3 gives 76% conversions in 50 min. Kinetic experiments reveal the involvement of two coppers in the cycloaddition process. Employing a host of substrates, the usefulness of fluorinated anions to dramatically improve the catalytic activity of Cu(I) compounds under on water conditions is demonstrated.
“Click Chemistry” in Zeolites: Copper(I) Zeolites as New Heterogeneous and Ligand-Free Catalysts for the Huisgen [3+2] Cycloaddition
作者:Stefan Chassaing、Abdelkarim Sani Souna Sido、Aurélien Alix、Mayilvasagam Kumarraja、Patrick Pale、Jean Sommer
DOI:10.1002/chem.200800479
日期:2008.7.28
For the first time, copper(I)-exchanged zeolites were developed as catalysts in organic synthesis. These solid materials proved to be versatile and efficientheterogeneous, ligand-free catalytic systems for the Huisgen [3+2] cycloaddition. These cheap and easy-to-prepare catalysts exhibited a wide scope and compatibility with functional groups. They are very simple to use, easy to remove (by filtration)