Palladium-Catalyzed Tandem Reactions To Form 1-Vinyl-1H-isochromene Derivatives1

Autor:	Eva M. Martin de la Nava, Ian B. Campbell, and Andy T. Merritt, Roger Mutter, Martin Wills
Rok vydání:	2001
Předmět:	chemistry.chemical_classification Allylic rearrangement Ketone Aryl Organic Chemistry chemistry.chemical_element Combinatorial chemistry chemistry.chemical_compound chemistry Pinacolone Organic chemistry Reactivity (chemistry) Protecting group Phosphine Palladium
Zdroj:	The Journal of Organic Chemistry. 66:3284-3290
ISSN:	1520-6904 0022-3263
Popis:	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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::3c672859b1d2f218dc39c75249b5f2ce https://doi.org/10.1021/jo0011991 Zobrazit plný text záznamu