Tel Aviv University (TAU)- Research Group
Prof. Moshe Portnoy
The Raymond and Beverly Sackler School of Chemistry
The Faculty of Exact Sciences
Tel Aviv University
Prof. Portnoy Moshe
Office phone: 972-3-6406517
Lab phone: 972-3-6406518
Office fax: 972-3-6409293
School of chemistry
Tel Aviv University
Tel Aviv 69978, Israel
Design and investigation of nanoscale dendritic composite materials for catalysis and biomedical applications Dendrimers are branched, highly ordered macromolecules that are assembled in a modular, iterative fashion from polyfunctional building blocks. These macromolecules are not only aesthetically appealing, but offer chemists three-dimensional structures of nanometer-range size with a variety of interesting architecture-dictated properties for a wide spectrum of applications. The modular mode of assembly and highly ordered nature of dendrimers make them especially suitable for the building of nanoscale devices. During the past few years, my group actively pursued the preparation of dendritic molecules on insoluble support as a platform for the generation of highly active and selective heterogeneous catalysts. We developed an efficient synthesis of new poly(arylbenzylether) dendrons on solid polymer support, functionalized their termini with catalytic units and explored their properties. An unprecedented positive dendritic effect on activity and chemoselectivity of a number of organometallic catalysts immobilized on such dendronized supports was revealed in a series of studies. Another group of catalysts that were immobilized on the dendronized supports are organocatalysts, small metal-free moieties capable of promoting selectively organic transformations of considerable complexity. For instance, we demonstrated a remarkable improvement in the efficiency and enantioselectivity of polymer-supported proline in the aldol and Mannich reactions upon dendritic spacer introduction. A tremendous increase in the catalyst activity upon dendronization of the support was also demonstrated for polymer-bound N-alkylimidazole catalysts in the Baylis-Hillman reaction. Our research in the field of supported dendritic catalysis is aimed at both understanding the rationale behind the dendritic effects as well as improvement and perfection of such systems for potential use. Recently, we began exploring dendrimers as platforms for diagnostic agents for molecular imaging.
Karabline J, Portnoy M. (2012) Solid-phase synthesis and acidolytic degradation of sterically congested oligoether dendrons. Org. Biomol. Chem. 10(24), 4788-4794.
Tuchman-Shukron L, Miller SJ, Portnoy M. (2012) Polymer-supported enantioselective bifunctional catalysts for nitro-Michael addition of ketones and aldehydes. Chemistry. 18(8), 2290-2296.
Karton-Lifshin N, Segal E, Omer L, Portnoy M, Satchi-Fainaro R, Shabat D. (2011) A unique paradigm for a Turn-ON near-infrared cyanine-based probe: noninvasive intravital optical imaging of hydrogen peroxide. J. Am. Chem. Soc. 133(28), 10960-10965.
K. Goren and M. Portnoy (2010) Supported N-alkylimidazole-decorated dendrons as heterogeneous catalysts for the Baylis-Hillman reaction, Chem. Commun. 46 (11), 1965-1967.
Mansour A, Kehat T, Portnoy M (2008) Dendritic effects in catalysis by Pd complexes of bidentate phosphines on a dendronized support: Heck vs. carbonylation reactions. Org Biomol Chem. 6(18), 3382-3387.
T. Kehat, K. Goren and M. Portnoy (2007) Dendrons on insoluble supports: synthesis and applications, New J. Chem. 31, 1218-1242.
A. Dahan and M. Portnoy (2007) Pd catalysis on dendronized solid support: generation effects and the influence of the backbone structure, J. Am. Chem. Soc. 129(18), 5860-5869.
A. Dahan and M. Portnoy (2003) Synthesis of poly (aryl-benzyl ether) dendrimers on solid support.Macromolecules 36, 1034-1038.
A. Dahan and M. Portnoy (2003) A remarkable dendritic effect in the polymer-supported catalysis of the Heck arylation of olefins, Org. Lett. 5, 1197-1200.
A. Dahan, A. Weissberg and M. Portnoy (2003) Preparation of novel polythioether dendrons on solid support, Chem. Commun., 1206-1207.
Tel Aviv University (TAU)
Ben-Gurion University of the Negev (BGU)
The Hebrew University of Jerusalem (HUJI)
Bar-Ilan University (BIU)