Organische Chemie

Springe direkt zu: Inhalt


Hauptnavigation/Hauptmenü: Links auf direkt erreichbare, übergeordnete Webseiten

Grafischer Identitätsbereich:

Navigation/Menü: Links auf weitere Seiten dieser Website und Banner


Home » Prof. Dr. Rainer Haag

Haag group - previous research topics

Dendritic polymers as high-loading supports for organic synthesis and catalysis

Polymer supports have been increasingly used in recent years for automated organic synthesis and catalysis. Cross-linked polystyrole resins have been used in the form of "microbeads," especially in solid phase chemistry. Some disadvantages of these solid phase supports are their low loading capacity (typically less than 1,5 mmol/g) and the heterogenic reaction conditions when used in organic solvents. Further development of special linker systems is still needed, which makes the production of functionalized carrier resins very expensive. Dendritic polymers, on the other hand, can be directly used as soluble supports with a high loading capacity for organic synthesis. The separation of the soluble polymers from the reaction mixture is based on membrane separation procedures (dialysis or ultrafiltration). Dendritic polyglycerol (PG) has proven to be especially advantageous for its easy accessibility, high chemical stability, and enormous loading capacity of up to 14 mmol/g. (Scheme 1) For example, carbonyl compounds or boronic acids can be directly coupled to the terminals of 1,2-diols of polyglycerols, chemically modified, and subsequently easily cleaved off again. Two goals of our current research are the synthesis of new drugs, e.g., gabapentine analogues as well as the use of reagents and catalysts on dendritic polyglycerol supports. (Schemes 2,3) Furthermore, new kinds of polystyrol-polyglycerol hybrid polymers (PS-PG) are being synthesized and examined for their suitability as high loading solid phase materials.

previous research 01


Scheme 1. Dendritic polyglycerol as a polymeric supports for the synthesis of carbonyl compounds.

previous research 02

Scheme 2. Dendritic PGs and PS-PG hybrid polymers as supports for reagents and catalysts.

previous research 03

Scheme 3. Dendritic salene catalyst for asymmetric Diels-Alder reactions.

For reviews see R. Haag, Chem. Eur. J. 2001, 7, 327; R. Haag, A. Hebel, J.-F. Stumbé, in Handbook of Combinatorial Chemistry, Eds. K.C. Nicolaou, R. Hanko, W. Hartwig, Wiley-VCH, Weinheim, 2002, 24; W. Bannwarth, R. Haag, et al., Angew. Chem. 2002, 114, 4136; Angew. Chem. Int. Ed. 2002, 41, 3694.

R. Haag, A. Sunder, A. Hebel, S. Roller, J. Combinatorial Chem. 2002, 4, 112.

A. Hebel, R. Haag, J. Org. Chem. 2002, 67, 9452.

A. Sunder, R. Mülhaupt, R. Haag, H. Frey, Adv. Mater. 2000, 12, 235

R. Haag, A. Sunder, J.-F. Stumbé, J. Am. Chem. Soc. 2000, 122, 2954.

S. Roller, H. Zhou, R. Haag, Molecular Diversity, 2005, 9, 305

C. Hajji, R. Haag, Topics in Organometallic Chemistry, 2006, 20, 149-176; C. Hajii, S. Roller, M. Beigi, A. Liese, R. Haag, Adv. Synth. Catal. 2006, 348, 1760-1771; A. Garcia Bernabé, C. C. Tzschucke, W. Bannwarth, R. Haag, Adv. Synth. Catal. 2005, 347, 1389

S. Roller, H. Türk, J.-F. Stumbé, W. Rapp, R. Haag, J. Combinatorial Chem. 2006, 8, 350



© 2009  Haag Research Group|   |
Stand: 11.11.2009

Diese Grafiken werden nur in der Druckvorschau verwendet: