Lithium acetate-catalyzed Michael reactionbetween trimethylsilyl enolates and α,β-unsaturated carbonyl compounds in DMF proceeded smoothly to afford the corresponding Michael-adducts in good to hi...
Synthesis of 4H-pyrans by O-cyclization of 1,5-diketones
作者:A. F. Blinokhvatov、O. V. Markovtseva、M. N. Nikolaeva
DOI:10.1007/bf00529364
日期:1992.3
Kharchenko, V. G.; Chalaya, S. N.; Litvinov, O. V., Journal of Organic Chemistry USSR (English Translation), 1984, vol. 20, # 6, p. 1098 - 1101
作者:Kharchenko, V. G.、Chalaya, S. N.、Litvinov, O. V.、Yudovich, L. M.、Promonenkov, V. K.
DOI:——
日期:——
Study of the state of rhodium in the potassium rhodiumundecatungstosilicate/alumina system by diffuse-reflectance IR spectroscopy
作者:P. A. Korovchenko、R. A. Gazarov、L. M. Kustov
DOI:10.1007/bf02495757
日期:2000.7
Adsorption of CO on the catalytic system K-5[SiW11RhO39]/Al2O3 was studied by diffuse-reflectance IR spectroscopy. The electronic state of rhodium and thermal stability of the system in the redox cycles were studied. The oxidized heteropolycompound (HPC) contains the charged forms Rh+, Rh2+, and Rh3+. Their ratio strongly depends on the pre-treatment temperature of the sample. In the reduced HPC two main forms of rhodium exist: the ionic Rh+ and metallic Rh-0. The supported HPC structure is stable in an oxidative medium at temperatures below -900 K. The properties of the K-5[SiW1 1RhO39]/Al2O3 system are retained in the redox cycles up to -670 K, and the highly dispersed state of rhodium is observed up to 900 K.