Dendrimer Assisted Solid Phase Synthesis of Heterobimetallic Asymmetric Catalyst

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Immobilization of catalysts on macromolecular supports fmilitates environmentally benign processes by enabling their recovery and reuse, The difficulty lies in orienting the ligands suitably on the support for the generation of the active catalyst. Random introduction of Iigands on the polymer restricts their application to moraonuclear catalysts and cannot be applicable to intricate catalysts such as the multicomponent consisting asymmetric catslyst, MAC (e.g. AlLibis(binaphthoxide) complex (ALB)). To overcome this difficulty, initially a dendnmersupported MAC was developed. Dendrimersupported MAC was found to catalyze various kinds of asymmetric reaction with high enantioeontnol. Recently we also presented a new concept for immobilizing MACs by copolymerization. A stable and easily replaceable catalyst analog was polymerized with a monomer in the presence of a crosslinker. Replacernent of the connecting group or element in the polymer with the catalytically active metal afforded the active catalyst. Thus the posifion and orientation of each ligand in the resulting polymers can be easily controlled. In addition soluble linear and dendronised polymers containing chiral binaphthol ligand were synthesized. These soluble polymnersupported MACs exhibited high catalyst activity in asymmetric synethesis. Highly effective synthesis of functionalized particles with spherical shape was also examnined.