Polymer-Mediated Reactions. A Nazarov-Like Cyclization
摘要:
The polymer PEDOT+ mediates a Nazarov-like cyclization of dienones, in an heterogeneous system and in hydrocarbon solvents. The polymer-mediated reactions show clear differences in product formation when compared to the same reaction with tosic acid, or when compared to reports in the literature. Comparable or improved yields are observed, as well as the ability to give a Nazarov product in cases where treatment with acid fails to give cyclization, or leads to an undesirable rearrangement. In addition, the ability to recycle the polymer makes this a potentially useful protocol for an important organic chemical reaction.
Silicon-DirectedNazarov Reactions II. Preparation and Cyclization of ?-Silyl-substituted Divinyl Ketones
作者:Todd K. Jones、Scott E. Denmark
DOI:10.1002/hlca.19830660802
日期:1983.12.14
Two general methods for the preparation of β-silyl-substituted divinyl ketones have been developed starting from either α, β-unsaturated aldehydes or simple ketones. Anhydrous FeCl3 induces the cyclization to cyclopentenones under mild conditions and in good yields with predictable and complete control over the position of the double bond in the five-membered ring. The observed effects of substituents