Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C-C bond forming reactions

Bagul, Rahul S and Jayaraman, Narayanaswamy (2012) Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C-C bond forming reactions. In: Journal of Organometallic Chemistry, 701 . pp. 27-35.

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Abstract

Dendrimers are ideal platforms to study multivalent effects due to the presence of uniform end groups at their peripheries. This report concerns with a study of multivalent dendritic catalysts, both within and across dendrimer generations, and their effects to mediate C-C bond forming reactions on multivalent substrates that have two and three acrylate reactive sites. As many as fourteen multivalent dendritic catalysts were prepared using 0-3 generations of poly(propyl ether imine) dendrimers, incorporated with Pd(II) catalytic sites, both within and across the dendrimer generations. C-C Bond forming reactions of these substrates with iodobenzene, mediated by uniform concentration of the metal across all catalysts, showed formation of partially and fully functionalized cinnamates in varying ratios, depending on the extent of clustering of catalytic moieties at the peripheries of dendrimers within a dendrimer generation. In a given generation, higher clustering of catalytic moieties greatly assisted multiple C-C bond formations than presenting the same in lesser number. The studies demonstrate true benefits of clustering catalytic moieties within a dendrimer generation and the beneficial effects applicable to catalysis of substrates presenting more than one reactive center. (C) 2011 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	Journal of Organometallic Chemistry
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Cluster effect;Dendrimers;Heck reaction;Multivalency; Organometallic catalysis;Palladium
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	22 Feb 2012 11:25
Last Modified:	22 Feb 2012 11:25
URI:	http://eprints.iisc.ac.in/id/eprint/43518

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