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854768 
Journal Article 
Metal vapour derived supported rhodium nanoparticles in the synthesis of β-lactams and β-lactones derivatives 
Aronica, LA; Caporusso, AM; Evangelisti, C; Botavina, M; Alberto, G; Martra, G 
2011 
Yes 
Journal of Organometallic Chemistry
ISSN: 0022-328X
EISSN: 1872-8561 
700 
20-28 
WOS:000299534600004 
Functionalised beta-lactones and beta-lactams were prepared starting from propargyl alcohols and propargyl tosyl amides by means of efficient silylcarbocyclisation reactions catalysed by rhodium nanoparticles derived from mesitylene-solvated Rh atoms (Metal Vapour Synthesis technique, MVS) and deposited on inorganic (C, gamma-Al2O3 Fe2O3) and organic matrices (PBI). All the MVS supported nanoclusters resulted more active than the analogous commercial Rh/C and Rh/gamma-Al2O3, as well as homogeneous Rh-4(CO)(12) used as reference catalyst. In particular, metal vapour derived Rh/C afforded the beta-lactones and beta-lactams in high yields and chemoselectivity. Preliminary investigations on the nature of the real active metal species involved in the catalytic process showed that rhodium(0) naked nanoparticles are leached by the support. The high catalytic activity encountered with Rh/C could be ascribed to the easy leaching of metal nanoparticles from carbon into solution. Indeed, the presence of a more polar matrix determined a minor catalytic efficiency probably due to a stronger interaction between the metal and the support. Therefore MVS Rh/C species represents a source, stable with ageing at room temperature, of highly active metal nanoparticles. (C) 2011 Elsevier B. V. All rights reserved. 
beta-Lactones; beta-Lactams; Silylcarbocyclisation; Supported rhodium nanoparticles; Metal vapour synthesis; Catalysis