Synthesis And Catalytic Properties Of Tin Complexes For Baeyer-Villiger Oxidation

The thesis consists of four parts as follows: Part I: ReviewsThis part reviewed the catalytic Baeyer-Villiger oxidation of ketones including metal-catalyzed oxidation and non-metal-catalyzed oxidation. In the first section, the author reviewed the metal-catalyzed oxidation from the following eight subsections, such as (i) Copper complex catalyzed system; (ii) Titanium complex catalyzed system; (iii) Cobalt complex catalyzed system; (iv) Platinum complex catalyzed system; (v) Zirconium complex catalyzed system; (vi) Rhenium complex catalyzed system; (vii) Scandium complex catalyzed system; (viii) Tin metals catalyzed system. Tin complex catalyzed system for the Baeyer-Villiger reaction was reported firstly by Corma and his co-workers in 2001. The application of tin complex catalyzed system in Baeyer-Villiger oxidation reactions was showed and the reaction mechanism was also given in this part. In non-metal-catalyzed oxidation section, the applications of inorganic compound catalyst and organic compound catalyst in Baeyer-Villiger catalytic oxidation reaction were showed particularly. A short conclusion was also proposed based on all of the reviews.Part II: Baeyer-Villiger oxidation of ketones with hydrogen peroxide catalyzed by Sn-palygorskitePalygorskite is a clay mineral that together with sepiolite from the group of fibrous clay minerals. A typical unit cell consists of Mg₅S₂0(OH₂) (H2O)4nH2O,with Mg preferentially located in octahedral sites. Palygorskite-supported Sn complexes were prepared by a simple procedure. Cyclic ketones and acyclic ketones were oxidized by hydrogen peroxide in a reaction catalyzed by palygorskite-supported Sn complex, affording corresponding lactones or esters with selectivity for the product of 90-100%. In particular, 2-adamantanone, 3-methyl-2-pentanone and 4-methyl-2-pentanone were converted into the corresponding lactone or ester almost quantitatively. In the case of 2-adamantanone, it is noteworthy that Sn-palygorskite as heterogeneous catalyst can be recycled at least 4 times without significant decline incatalytic activity.Part III: Baeyer-Villiger oxidation of ketones with hydrogen peroxide catalyzed by anilin-Sn and PS-Sn complexesAnilin-Sn and PS-Sn catalysts were prepared firstly by a simple procedure. The Baeyer-Villiger oxidation of 2-adamantanone was investigated and the optimized conditions for the oxidation were proposed. Then the oxidation of other cyclic ketones and acyclic ketones with these tin-containing catalysts and hydrogen peroxide under the optimum conditions were carried out according to the optimizing reaction conditions. The results show that anilin-Sn and PS-Sn complexes are excellent catalysts for Baeyer-Villiger catalytic oxidation of cyclic ketones and acyclic ketones. Compared to PS-Sn complex catalyst, anilin-Sn catalyst bears more excellent catalytic activity for catalytic Baeyer-Villiger oxidation reaction and many ketones can be oxidized to the corresponding lactone or e ster w ith high c onversion and selectivity with 30% H2O2 within short reaction time. However, low molecular weight complex catalyst c an n ot b e r ecycled, b ut P S-Sn c omplex c an b e r ecycled for s everal t imes without significant decline in catalytic activity. Part IV: Baeyer-Villiger oxidation of ketones with hydrogen peroxide catalyzedby a benzyl alcohol-Sn and PS-Sn complexesBenzyl Alcohol-Sn and PS-Sn complexes catalysts were prepared firstly by a simple procedure. A variety of cyclic ketones and acyclic ketones were oxidized by 30% H2O2 to the corresponding lactone or ester in the presence of with benzyl alcohol-Sn and PS-Sn complexes catalysts according to the optimum conditions obtained from the investigation of the catalytic oxidation of 2-adamantanone with benzyl alcohol-Sn and PS-Sn catalysts complexes catalysts respectively. Benzyl alcohol-Sn complex is more excellent catalyst for Baeyer-Villiger catalytic oxidation reactions comparatively to PS-Sn complex. The advantage of PS-Sn complex catalyst compared to benzyl alcohol-Sn complex catalyst is PS-Sn complex catal...