Polymer aldehydes, transfer hydrogenation

A few benzisoselenazol-3(2//)-oncs were covalently immobilized to the solid support, either silica [165] or polymer [246] (147-150) (Fig. 8). They exhibited appreciable catalytic activity similar to the activity of ebselen. The most interesting prospective oxygen-transfer catalyst is benzisoselenazolone covalently bound to a silica support (147) named HALICAT. It has been applied to hydrogen peroxide oxidation of the sulfides and TBHP oxidation of the aromatic aldehydes and alky-larenes. The catalyst can be easily filtered off from the mixture after the reaction and reused several times [165],... 

The group of Nomura has explored the end-functionalization of molybdenum carbene initiated ROMP polymers extensively. Terminal monool [81, 82] or diols [83] were prepared via ROMP and used to synthesize different copolymer architectures. Pyridine and bi-pyridine ligands were successfully introduced to the polymer chain end in order to complex to ruthenium carbenes. Polymeric recyclable hydrogen transfer reduction catalysts were prepared in this manner [84, 85]. Notestein et al. [86] used a polymeric mono-aldehyde to functionally terminate a living ROMP initiated with a molybdenum catalyst to prepare diblock copolymers during the end-capping step. 

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