Polyvinyl pyrolidone-supported chlorochromates: preparation and application as solid phase synthetic oxidising reagent

Abstract

Crosslinked 1-vinyl pyrolidone was prepared using divinylbenzene in different proportions by free radical suspension copolymerisation. The resulting crosslinked poly(vinyl pyrolidone) resins containing 3, 10, 15 and 20% of the crosslinking agents were converted to chlorochromate derivatives by treatment with CrO₃ and HCl. The extent of functionalisation was decreased with increasing amount of crosslinking agent and the capacity ranging from 4.3 to 2.1 mequiv./g. Alcohols were oxidised to the corresponding carbonyl compounds in near quantitative yield using these resins. The interdependency of the extent of crosslinking, the hydrophobic–hydrophilic nature of the polymer system used and the preparative applications of these resins in organic chemistry are described. These studies revealed that the optimum condition for a specific extent of reaction can be arrived by a judicious choice of the factors like the mechanical integrity of the particles, hydrophobic–hydrophilic nature of the solvents, molar excess of the polymeric reagent and temperature.