Palladium-catalyzed tandem reactions to form 1-vinyl-1H-isochromene derivatives
UNSPECIFIED. (2001) Palladium-catalyzed tandem reactions to form 1-vinyl-1H-isochromene derivatives. JOURNAL OF ORGANIC CHEMISTRY, 66 (10). pp. 3284-3290. ISSN 0022-3263Full text not available from this repository.
Official URL: http://dx.doi.org/10.1021/jo0011991
The palladium-catalyzed reaction of pinacolone with tert-butyldimethyl(3-(2-bromophenyl)allyloxy)-silane results in direct formation of 1-vinyl-3-tert-butyl-1H-isochromene. This is the result of a ketone arylation followed by an intramolecular cyclization of the enolate with the allylic system. The use of a lithium diamide base appears to be essential for success. The tert-butyldimethylsilyl protecting group is also an essential choice as it furnishes the appropriate reactivity to promote allylic substitution after the aryl coupling process. The use of more effective leaving groups, such as acetate, results in reaction of the allylic group, and no aryl coupling is observed. Through the appropriate selection of phosphine ligand and solvent, either the cyclized isochromene product or the noncyclized intermediate may be formed selectively. A short combinatorial study of the scope and limitations of the reaction, involving 24 ketones, is described.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Journal or Publication Title:||JOURNAL OF ORGANIC CHEMISTRY|
|Publisher:||AMER CHEMICAL SOC|
|Date:||18 May 2001|
|Number of Pages:||7|
|Page Range:||pp. 3284-3290|
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