氮羟基邻苯二甲酰亚胺催化的α-紫罗兰酮的氧化反应

以分子氧（O₂）为氧化剂，在无溶剂条件下，研究了N-羟基邻苯二甲酰亚胺/乙酰丙酮亚钴(Ⅱ)体系对α-紫罗兰酮的催化氧化反应，分析了氧化产物，主要得到α-紫罗兰酮的烯丙位氧化产物5-氧代-α-紫罗兰酮，同时生成少量环氧α-紫罗兰酮及重排产物4-氧代-β-紫罗兰酮和环氧β-紫罗兰酮，提出了可能的反应机理，化合物的结构经IR, ¹H NMR, MS和EA等手段得以表征；为了提高5-氧代-α-紫罗兰酮的选择性和催化氧化反应的转化率，优化了催化氧化反应的工艺条件：当反应温度为70 ℃，氧气压力为1.0 MPa，N-羟基邻苯二甲酰亚胺和乙酰丙酮亚钴(Ⅱ)用量分别为α-紫罗兰酮的25%和1.0%，反应10 h，5-氧代-α-紫罗兰酮的产率达53.4%，反应转化率达95.0%以上，平行实验表明，实验重复性良好。

Aerobic oxidation of α-ionone catalyzed by N-hydroxyphthalimide(NHPI) combined with Co(acac)2

A practical catalytic method to oxidize α-ionone with molecular oxygen under normal pressure and temperature using N-hydroxyphthalimide (NHPI) combined with Co(acac)2 was developed, and probable catalytic mechanism was proposed. Influences of the reaction conditions on conversion of α-ionone and the selectivity of the major product (5-keto-α-ionone) were investigated, the optimal technical parameters for 5-keto-α-ionone were optimized. The results show that the primary products are 5-keto-α-ionone, epoxy-α- ionone, as well as rearrangement products 4-keto-β-ionone and epoxy-β-ionone, which are characterized by infrared spectra, proton nuclear magnetic resonance spectra, mass spectra and elemental analyzer; The yield of 5-keto-α-ionone and the conversion of α-ionone are 53.4% and 95.0%, respectively, when 25 % NHPI, 1.0% Co(acac)2 (in mole ratio) and no solvent is employed under O2 pressure for 1.0MPa and the reaction temperature at 70℃ for 10h, the procedure shows good reproducibility in the parallel experiments.