Reaction-Controlled Phase-Transferred Catalysis for Alcohols Selective Oxidation with 30 H_2O_2

摘要

The oxidation of alcohols into the corresponding carbonyl compounds is one of the most frequently used synthetic reactions. The traditional oxidation of alcohols are performed with stoichiomertric amounts of inorganic oxidants, notably chromium (Ⅵ) regents. However, these oxidants posses the serious disadvantage,such as expensive and/or toxic. From both an economic and environmental viewpoint these is a growing demand for atom efficient, catalytic methods that employ clean oxidants such as O_2 and H_2O_2. A number of procedures for alcohol oxidation using H_2O_2 with metal complexes have been reported We describe the alcohols selective oxidation with reaction-controlled phase-transfer catalyst. The catalyst can form soluble active species with H_2O_2 that subsequently react with secondary alcohol to selectively generate the corresponding ketones. When the oxidation finished, the catalyst precipitates from the reaction medium, which can then be easily separated and reused, thus providing a useful approach to the difficult problem of the separation of homogenous catalysts.