Polystyrene-graft-polyglycerol resins: a new type of high-loading hybrid support for organic synthesis.

The preparation of a dendritic graft polymer by a very efficient synthesis of polyglycerol directly on a polystyrene resin is presented. This one-step process can be performed on a multigram scale to provide a chemically stable polymeric support. The resulting hybrid polymers were fully characterized by diverse analytical methods (NMR, IR, ESEM, UV detection of cleaved protecting groups, and mass-spectrometric methods).

Electrolysis as an efficient key step in the homogeneous polymer-supported synthesis of N-substituted pyrroles.

[reaction: see text]. An efficient and general route to the soluble polymer-assisted synthesis of a set of 14 different N-substituted pyrroles using dendritic polyglycerol as a high-loading support is presented. The transformation of furan to the key intermediate 2,5-dialkoxytetrahydrofuran was performed by electrochemical oxidation followed by catalytic hydrogenation with Pt/C in high yield.

High-loading polyglycerol supported reagents for Mitsunobu- and acylation-reactions and other useful polyglycerol derivatives.

In this paper we present soluble dendritic polyglycerol (PG) supported reagents PG-DEAD, PG-PPh3, and PG-DCC as well as scavengers PG-carbonate, PG-carbazate, and PG-amine, which all have been synthesized in high overall conversions and yields using simple purification techniques. The supported reagents have been used simultaneously in Mitsunobu and acylation reactions. All polymeric reagents and scavengers can be removed by simple precipitation/filtration protocols to give chromatography-free products of high purity.

Polymeric supports for the immobilisation of catalysts.

This chapter summarises the most frequently used polymeric supports for catalysis and highlights some recent developments in the field. Two classes of polymers, crosslinked solid phase supports and non-crosslinked soluble polymeric supports, are discussed with the focus on covalently attached catalysts. In addition, for soluble polymeric supports the different separation techniques are critically compared and evaluated for their application in catalysis.

Modern separation techniques for the efficient workup in organic synthesis.

The shift of paradigm in combinatorial chemistry, from large compound libraries (of mixtures) on a small scale towards defined compound libraries where each compound is prepared in an individual well, has stimulated the search for alternative separation approaches. The key to a rapid and efficient synthesis is not only the parallel arrangement of reactions, but simple work-up procedures so as to circumvent time-consuming and laborious purification steps. During the initial development stages of combinatorial synthesis it was believed that rational synthesis of individual compounds could only be achieved by solid-phase strategies.

Dendritic aliphatic polyethers as high-loading soluble supports for carbonyl compounds and parallel membrane separation techniques.

This paper describes the use of dendritic polyglycerol as a new high-loading polymeric support. The soluble polyether skeleton allows the parallel synthesis of small libraries on a large scale (1-5 mmol). Purification of polymer-bound products is easily achieved by a parallel dialysis apparatus, which was developed to separate up to 12 reaction mixtures simultaneously.