Study On Catalytic Dihydroxylation Of Olefins: An Metal-Free System

1,2-Diols are widely used as intermediates in the perfume and fragrance industry,forthe manufacture of cosmetics, for the synthesis of commercial products such asphotographic materials and lubricants, and in drugs and foods. Dihydroxylation ofolefins is a straightforward method for the synthesis of 1,2-diols, and various oxidantsare now used for this purpose both in the laboratory and in industry. The syndihydroxylation of olefins is most commonly performed in the presence of metaloxides, including KMnO₄ and OsO₄, and t-C4H9OOH with a catalytic amount of OsO₄.Unfortunately, many metals are toxic, which presents sustainability and environmentalchallenges. The dihydroxylation can also be achieved with CH₃CO₃H andm-ClC₆H₄CO₃H in water. However, the atom efficiency of these oxidants is low, andthey form equimolar amounts of the deoxygenated compounds as waste. Hydrogenperoxide is an ideal oxidant, because water is theoretically the sole by-product.However, H₂O₂ can be a clean oxidant only if it is used in a controlled manner withoutorganic solvents and other toxic compounds. In this context, we developed a oxidationreactions with aqueous H2O2 under organic-solvent-free conditions.GO is typically prepared from natural sources of flake graphite using stronglyacidic and oxidizing conditions. The most commonly employed synthetic protocol isoften called the'Hummers method,'where graphite is treated with KMnO4 inconcentrated H₂SO₄, followed by workup in aqueous H₂O₂. Though the precisestructure of GO is still uncertain, it is generally accepted that a wide range offunctional groups, including alcohols, epoxides, and carboxylic acids, are introducedduring the synthesis of GO, both to its surface as well as to its periphery. As a result,GO tends to be highly acidic and strongly oxidizing, and exhibits a high propensity toundergo reduction when exposed to hydrazine, borohydride, and other reagents. Indeed,GO is commonly used as an intermediate in the preparation of graphene andgraphene-like materials. Graphene－a flat monolayer of carbon atoms tightly packedinto a two dimensional honeycomb lattice was discovered in 2004. Due to its unusualmolecular structure, grapheme shows many novel and unique physical and chemicalproperties, which are generating much attention in both the communities of scienceand industry.Herein,we the use of graphite oxide (GO) as a catalyst,H₂O₂ or t-C4H9OOH as aoxidant for oxidizing styrene. We optimize the reaction conditions. Compared to other catalyst used for similar purposes, GO offers several advantages, including low cost,ease of synthesis, and high stability to ambient conditions. In summary, we havedeveloped a clean and safe method for the dihydroxylation of phenylethylene underorganic-solvent- and metal-free conditions. The graphite oxide catalyst is easilyrecycled .