Control of the Regioselectivity in Catalytic Transformations Involving Amphiphilic Bis-allylpalladium Intermediates: Mechanism and Synthetic Applications
2001 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 66, no 5, 1686-1693 p.Article in journal (Refereed) Published
Various dialkyl-substituted allyl chloride derivatives (2d−i) undergo regioselective palladium-catalyzed coupling reactions with allylstannanes (1a,b) and benzylidenemalonitrile (4), providing functionalized 1,7-octadienes in good yield. The catalytic reaction proceeds through an unsymmetrical amphiphilic bis-allylpalladium intermediate. An introductory electrophilic attack on the terminal position of the unsubstituted allyl moiety is followed by a nucleophilic attack on the alkyl-substituted allyl ligand. A theoretical analysis was performed by applying density functional theory at the B3PW91/DZ+P level to study the substituent effects on the electrophilic attack. According to the theoretical results, the high regioselectivity can be ascribed to the electronic effects of the alkyl substituents: The terminal alkyl groups destabilize the η1,η3-bis-allylpalladium intermediate of the reaction; in addition, the alkyl substitution increases the activation barrier for the electrophilic attack.
Place, publisher, year, edition, pages
2001. Vol. 66, no 5, 1686-1693 p.
IdentifiersURN: urn:nbn:se:su:diva-22711DOI: 10.1021/jo001374dOAI: oai:DiVA.org:su-22711DiVA: diva2:189304
Part of urn:nbn:se:su:diva-1052004-04-222004-04-222010-07-27Bibliographically approved