Dispersed Gold Nanoparticles Supported in the Pores of Siliceous Mesocellular Foam: A Catalyst for Cycloisomerization of Alkynoic Acids to gamma-Alkylidene Lactones
2015 (English)In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 10, 2250-2255 p.Article in journal (Refereed) Published
A versatile approach for the production of dispersed thiol-stabilized gold nanoparticles in the pores of siliceous mesocellular foam (MCF) is described. The reported method is based on an electrochemical oxidation of a gold surface generating oxidative Au-III species, which give rise to a surface-confined redox reaction yielding MCF-supported Au-I thiolates. By reducing the corresponding Au-I-S-MCF species with sodium borohydride, thiol-stabilized gold nanoparticles in the size range of 1-8 nm were obtained as determined by transmission electron microscopy. Elemental analysis indicated an Au loading of 3% (w/w) on the MCF. The surface-confined Au nanoparticles were used to catalyze the cycloisomerization of alkynoic acids to the corresponding -alkylidene lactones in high efficiency and complete 5-exo-dig selectivity under mild reaction conditions.
Place, publisher, year, edition, pages
2015. no 10, 2250-2255 p.
Cycloisomerization, Alkynoic acids, Nanoparticles, Gold, Heterogeneous catalysis
IdentifiersURN: urn:nbn:se:uu:diva-252185DOI: 10.1002/ejoc.201403664ISI: 000352110600020OAI: oai:DiVA.org:uu-252185DiVA: diva2:810136