Phosphorus Molybdate Catalyzed By Molecular Oxygen Oxidation Of ¦Â-ionone And Load The Preparation And Properties Of The Phosphorus Molybdate Catalyst

4-oxo-β-ionone is an important flavor and chemical intermediates compounds, which can be used in food, makeup and medicament widely. It can be abstracted from plants but the amount of that is very little, which can't meet the demands of people. Furthermore, its cost is very high. So seeking an effective and environmental chemical method to synthsize it is very important. Our work team have achieved some success, but there are also some troubles such as low selectivity of oxo-product and inconvenient of post-processing. On base of foregoing work, the reseach works below have been done:At first, the oxidation ofβ-ionone catalyzed by PMA has been performed, andβ-ionone was oxidized to 4-oxo-β-ionone as the main product, and the influence of a series of different conditions for the reaction was investigated. In DMSO, utilizing O2 as he oxidant, PMA as catalyst and t-BuOK as additives has been perfected:(1) To a solution ofβ-ionone(0.026mol) in DMSO(20mL) in a three-necked flask equipped reflux condencer was added PMA(0.43mol%) and 1mmol t-BuOK, the mixture was heated to 115℃and stirred for 20h under 1atm O2. The conversion ofβ-ionone is 100% and selectivity of 4-oxo-(3-ionone is also 75%.Also, different PMA catalysts are prepared supported by silica gel, activated carbon and molecule sieve. And the catalysts are used in allylic oxidation acetylation reactions. The results show:the catalyst is easy to separate and recycle when it is supported on carriers. When supported catalyst is used in acetylation reactions, it get rid of some dificiencies of traditional catalyts, such as heavy corruption, pollution of environment and huge usage of catalysts.At last, the method of return flow is adopted to prepare PMA/SiO2, and take catalytic oxidation ofβ-ionone as a reaction model, reaction press, the humid of oxygen, amount, size and acidity of silica gel are investigated to optimize the reaction condition. Using PMA/SiO2 as catalyst,β-ionone can be catalytic oxidized to 4-oxo-β-ionone with 100% conversion and 72.8% selectivity. The supported catalyst can be reused for 4 times with high conversion and selectivity. And also, a series of alkenes, such asα-ionone,β-methyl-iononeare also oxidized to corresponding allylic products with conversion from 79.6% to 100%, selectivity from 60.7% to 75.2%.