Polymer bound proline

Couple protected leucine to the deprotected, polymer-bound proline ... 

Kondo, K., Yamano, T., Takemoto, K. Functional monomers and polymers, 129. Asymmetric Robinson cyclization reaction catalyzed by polymer-bound L-proline. Makromol. Chem. 1985,186,1781-1785. 

Metal ion complexes. These classic CSPs were developed independently by Davankov and Bernauer in the late 1960s. In a typical implementation, copper (II) is complexed with L-proline moieties bound to the surface of a porous polymer support such as a Merrifield resin [28-30]. They only separate well a limited number of racemates such as amino acids, amino alcohols, and hydroxy acids. 

Very recently, Portnoy et al. described the design and synthesis of insoluble polymer-supported dendrimers bearing proline end groups for asymmetric aldol reachons [123]. The zeroth- to third-generahon supported dendrimer catalysts were prepared by ahaching (2S,4R)-4-hydroxyproline onto the insoluble PS-bound... 

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