"Click Chemistry" in Zeolites: Copper(I) Zeolites as New Heterogeneous and Ligand-Free Catalysts for the Huisgen [3+2] Cycloaddition

• Published in: Chemistry : a European journal 2008-07, Vol.14 (22), p.6713-6721
• Main Authors: Chassaing, Stefan, Sani Souna Sido, Abdelkarim, Alix, Aurélien, Kumarraja, Mayilvasagam, Pale, Patrick, Sommer, Jean
• Format: Article
• Language: English
• Subjects: click chemistry; copper; cycloaddition; heterogeneous catalysis; zeolites
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200800479

For the first time, copper(I)‐exchanged zeolites were developed as catalysts in organic synthesis. These solid materials proved to be versatile and efficient heterogeneous, 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), and are recyclable (up to three times without loss of activity). Investigations with deuterated alkynes and deuterated zeolites proved that this CuI‐zeolite‐catalyzed “click” reaction exhibited a mechanism different from that reported for the Meldal–Sharpless version. Click in zeolites! Copper(I) zeolites are practical, highly versatile, and efficient catalysts for the Huisgen cycloaddition (see scheme). These cheap catalysts thus fulfill the “click chemistry” criteria. Mechanistic investigations reveal that this heterogeneous version of the Huisgen click reaction follows a pathway different from the Meldal–Sharpless version.