An Example of Lipophiloselectivity:  The Preferred Oxidation, in Water, of Hydrophobic 2-Alkanols Catalyzed by a Cross-Linked Polyethyleneimine−Polyoxometalate Catalyst Assembly

A cross-linked polyethyleneimine polymer containing the [ZnWZn₂(H₂O)₂(ZnW₉O₃₄)₂]^12- polyoxometalate was prepared from branched polyethyleneimine (M_w = 600), the polyoxometalate, and a n-octylamine-epichlorohydrin cross-linking reagent. This catalytic assembly was active for the selective oxidation of 2-alkanols to 2-alkanones with aqueous H₂O₂ with reactions presumably occurring at a hydrophobic domain. Most importantly, the catalyst showed distinctive lipophiloselectivity, that is selectivity as a function of the lipophilic nature of a reaction substrate. The lipophiloselectivity was proportional to the relative partition coefficient (1-octanol/water) of the substrates.