Metal catalysis in organic reactions. Part 13. The reaction of 3-en-1-ynes with trialkylalanes: influence of transition-metal complexes
作者:Anna Maria Caporusso、Giampaolo Giacomelli、Luciano Lardicci
DOI:10.1039/p19810001900
日期:——
The reaction between trialkylalanes and 3-alkyl-, 4-alkyl-, or 3,4-dialkyl-but-3-en-1-ynes (1) leads to products which correspond to metallation, reduction, and carbalumination processes. The extent of such reactions, and the regio- and stereo-selectivity of the carbalumination, are dependent on the enyne used. A mechanism is proposed involving tautomeric equilibria among several α-unsaturated organoaluminum
Surface-Mediated Reactions. 6. Effects of Silica Gel and Alumina on Acid-Catalyzed Reactions
作者:Paul J. Kropp、Gary W. Breton、Stephen L. Craig、Scott D. Crawford、William F. Durland、John E. Jones、J. Scott Raleigh
DOI:10.1021/jo00118a035
日期:1995.6
Adsorption of a variety of acids to chromatographic silica gel results in substantial enhancement of their catalytic activity-affording easily prepared, environmentally benign heterogeneous acids that are highly effective in mediating a number of processes. This was shown for the isomerization of allene 1 and dimerization of the corresponding 1,3-diene 2; cyclization of (R)-citronellal (5), the related diester 10, and 1,5-cyclooctadiene (15); Rupe rearrangement of alkynol 18; and Friedel-Crafts cyclodehydration of alcohols 21. By contrast, commercially available Nafion-H was significantly less effective as a heterogeneous acid catalyst. Chromatographic alumina displayed enigmatic behavior, showing enhanced acidity on the adsorption of HCl but little or no acidity on the adsorption of a variety of other types of acid. The results are discussed in terms of the surface structures of silica gel and alumina.
Caporusso, Anna Maria; Lardicci, Luciano; Settimo, Federico da, Gazzetta Chimica Italiana, 1986, vol. 116, # 10, p. 599 - 602
作者:Caporusso, Anna Maria、Lardicci, Luciano、Settimo, Federico da
DOI:——
日期:——
Ohanessian, Gilles; Six, Yvan; Lallemand, Jean-Yves, Bulletin de la Societe Chimique de France, 1996, vol. 133, # 11, p. 1143 - 1148