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.
Peiffer,G. et al., Bulletin de la Societe Chimique de France, 1969, p. 4117 - 4123
作者:Peiffer,G. et al.
DOI:——
日期:——
Traynard,J.-C., Bulletin de la Societe Chimique de France, 1962, p. 19 - 22
作者:Traynard,J.-C.
DOI:——
日期:——
Bertrand,M.; Le Gras,J., Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1963, vol. 257, p. 456 - 458