MCM-41固载Co席夫碱配合物的制备及其催化烯烃环氧化的研究

环氧化合物作为有机合成中间体具有广泛应用,催化烯烃环氧化一直是催化化学中的一个重要课题[1～2].尽管已经报道了以过酸、过氧化氢、烷基过氧化物、或分子氧为氧化剂,以金属配合物(通常为钌、钼、钛的配合物)为催化剂的反应体系,但对环氧化物的选择性却很低[3].另外,除了需探索具有高选择性的催化体系外,应用分子氧或空气作为氧化剂更适宜于经济和安全的要求.目前,在以分子氧作为氧化剂,均相催化烯烃环氧化的研究中,应用醛类化合物作为氧转移试剂是一种有效的和方便的促进烯烃环氧化的方法[4].但是,均相催化剂难于分离和重复使用,因此…     

金催化氧化末端炔烃合成α-乙酰氧基甲基酮方法研究

采用Ph3PAuNTf2作为催化剂,8-甲基喹啉氮氧化物为氧化剂,甲基磺酸为添加酸,金催化氧化末端炔烃与乙酸分子反应,室温下高效合成了一系列α-乙酰氧基甲基酮化合物.考察了氧化剂、催化剂结构、催化剂用量等因素对反应的影响,确定了最优反应条件,最高收率为90%.提出了α-羰基金卡宾对乙酸分子O—H键的卡宾反应机理.该方法具有操作简单、条件温和、产率高等特点,为含有α-乙酰氧基甲基酮结构的化合物合成提供了一条新的途径.     

钴(Ⅱ)催化2-乙基-3-甲基吡嗪绿色氧化方法

以过氧化叔丁醇为氧化剂,以钴(Ⅱ)与含N配体为催化体系催化氧化2-乙基-3-甲基吡嗪(EMP),提出一种具有放大应用前景的2-乙酰基-3-甲基吡嗪绿色制备方法.考察了过渡金属催化剂的种类、配体种类、溶剂、温度等反应条件对催化氧化过程的影响,在最优反应条件下EMP转化率可达58.8%, 2-乙酰基-3-甲基吡嗪(AMP)选择性92.2%.研究了该反应体系催化氧化EMP的反应机理,建立了该反应的拟均相反应动力学模型.在以上实验基础上,对该反应体系进行了放大实验研究,结果表明该新方法具有较好的工业放大前景,但反应温度的控制是放大过程的关键因素.     

α，β-不饱和酮的绿色环氧化

以过氧化氢为氧源,磷钨杂多酸季铵盐为催化剂,研究了α,β-不饱和酮的环氧化反应,考察了溶剂、温度、催化剂用量、反应时间以及底物浓度等因素对环氧化反应的影响. 结果表明,在适宜反应条件下,过氧化氢/磷钨杂多酸季铵盐催化体系可以催化α,β-不饱和酮环氧化,得到相应的环氧化合物,并能取得较好的结果. 其中, 4-甲基-3-戊烯-2-酮的环氧化合物的产率达到了87%.     

钴(Ⅱ)催化2-乙基-3-甲基吡嗪绿色氧化方法（英文）

以过氧化叔丁醇为氧化剂,以钴(II)与含N配体为催化体系催化氧化2-乙基-3-甲基吡嗪(EMP),提出一种具有放大应用前景的2-乙酰基-3-甲基吡嗪绿色制备方法.考察了过渡金属催化剂的种类、配体种类、溶剂、温度等反应条件对催化氧化过程的影响,在最优反应条件下EMP转化率可达58.8%, 2-乙酰基-3-甲基吡嗪(AMP)选择性92.2%.研究了该反应体系催化氧化EMP的反应机理,建立了该反应的拟均相反应动力学模型.在以上实验基础上,对该反应体系进行了放大实验研究,结果表明该新方法具有较好的工业放大前景,但反应温度的控制是放大过程的关键因素.     

铜催化的芳基酮及其衍生物氧化酰胺化合成α-酮酰胺的反应研究

研究了在水相体系下芳基酮类化合物与胺类化合物的氧化酰胺化合成α-酮酰胺的反应.室温条件下,以过氧叔丁醇(TBHP)为氧化剂,芳基酮与胺类化合物在铜盐与分子碘的协同作用下高效地得到了目标产物.同时研究了在以氧气为氧化剂的条件下,铜催化的酰基乙酸酯及其衍生物的C—C键断裂实现α-酮酰胺的合成.     

溴过氧化物酶催化环己烯环氧化反应

研究了分离自珊瑚藻(Corallina officinalis)的溴过氧化物酶在水-有机两相体系中催化环己烯环氧化的反应.考察了氧化剂种类与添加方式、pH、反应温度、酶浓度及KBr浓度等条件对环氧化反应的影响.最佳反应条件为:反应温度55℃,在含有50mmol/LKBr和32U/ml溴过氧化物酶的pH6.0的Tris-HCl缓冲液中,每隔10min补加50μl的2.29mol/LH2O2.在此反应条件下,环氧环己烷的收率达到41.5%,选择性为82.2%.     

新型钨酸盐的合成及催化环氧化环戊烯反应

合成了新型喹啉十聚钨酸盐化合物[C3Quin]4W10O32,并对该化合物催化环氧化环戊烯的反应进行研究.考察了催化剂([C3Quin]4W10O32),氧化剂(UHP),反应溶剂([Bmim]BF4)和反应时间等因素对反应收率的影响,优化出最佳反应条件:在反应温度35℃,环戊烯1mmol,催化剂15μmol,氧化剂2.5mmol,离子液体0.4mL,反应时间8h,环氧环戊烷产率达到99%.     

生物油脂新型环氧化过程及机理研究

以金属有机化合物甲基三氧化铼(MTO)为催化剂, 双氧水为氧化剂新型化学方法合成环氧大豆油. 详细考察了催化剂在双氧水、溶剂和助剂等因素下的催化性能. 研究了该催化体系在其他油脂环氧化中的应用, 环氧产物的选择性在99%以上. 采用红外光谱法(IR)对产品进行表征. 通过紫外-可见分光光度法(UV-Vis)对催化剂的研究, 发现催化剂(MTO)在催化环氧化过程中形成催化中间体, 且催化活性很高. 对催化剂和双氧水相互作用机理及新型环氧化反应的机理进行了初步研究.     

Lewis碱催化合成三氟甲基硅与羰基化合物反应合成α-三氟甲基醇

通过路易斯碱催化三氟甲基硅与羰基化合物的反应，合成一系列α-三氟甲基醇化合物。同时还发现，在碱性条件下，该反应存在产物自催化现象，充分体现了绿色化学的原子经济性原则。     

Keggin类杂多化合物催化α,β-不饱和羰基化合物环氧化

在乙睛溶剂中考察了一系列杂多化合物和过氧化氢水溶液催化的各种缺电子的α,β-不饱和羰基化合物的环氧化反应.在所研究的杂多化合物中,二缺位的[γ-SiW10(H2O)2O34](Bu4N)4显示出了最高的活性.     

Activity and behavior of imidazolium salts as a phase transfer catalyst for a liquid-liquid phase system

The structure-activity relationship and behavior of N,N′-dialkylimidazolium salts as a phase transfer and/or ion-exchange catalyst in a liquid-liquid phase system were investigated for the reactions such as β-elimination reaction of alkyl halides, nucleophilic epoxidation of α,β-unsaturated carbonyl compounds, alkylation of active methylenes, and nucleophilic substitution reaction.     

An Effective Synthesis of β- Selenium and β- Tellurium Carbonyl Compounds Via Reaction of Diaryldiselenides Or Diarylditellurides with α,β- Unsaturated Carbonyl Compounds Induced by Low-Valent Titanium

P-Selenium and β-tellurium carbonyl compounds have been prepared in good yield by reaction of diaryldiselenides or diarylditelluride with α,β-unsaturated carbonyl compounds induced by TiC1₄ / Sm /THF system under mild reaction conditions.     

Unusual reaction of β-hydroxy α-diazo carbonyl compounds with TsNHNCHCOCl/Et3N

The reaction of β-hydroxy α-diazo carbonyl compounds with TsNHNCHCOCl/Et₃N gave β-(p-tolylsulfonyl) α,β-unsaturated carbonyl compounds or β-(p-tolylsulfonyl) α-diazo esters. The reaction mechanism is discussed.     

Heterogeneous Baeyer-Villiger oxidation of ketones with H2O2/nitrile, using Mg/Al hydrotalcite as catalyst

We synthesized a magnesium-aluminium hydrotalcite and used it as a catalyst in the Baeyer-Villiger (BV) oxidation of cyclohexanone with a mixture of 30% aqueous hydrogen peroxide and benzonitrile as oxidant. The hydrotalcite proved an excellent catalyst for the process. The influence of experimental variables was examined in depth in order to bring the working conditions as close as possible to those usable on an industrial scale. We optimized the cyclohexanone/hydrogen peroxide/benzonitrile proportion and used various nitriles, solvents and amounts of catalyst, benzonitrile and methanol proving the most effective nitrile and solvent, respectively, for the intended purpose. The reaction was found to occur to an acceptable extent with other carbonyl compounds as substrates; by exception, α,β-unsaturated carbonyl compounds provided poor results by effect of their undergoing competitive epoxidation of their double bonds.     

Highly efficient epoxidation of electron-deficient olefins with tetrabutylammonium peroxydisulfate

The epoxidation of α,β-unsaturated carbonyl compounds such as enones and enals was efficiently achieved with tetrabutylammonium peroxydisulfate in the presence of equimolar amounts of hydrogen peroxide and NaOH in acetonitrile or methanol at 25 °C in excellent yields. Base-sensitive substrate such as cinnamaldehyde could be successfully epoxidized in short reaction time under mild reaction conditions.     

烯胺与全卤代氟卤乙烷的亲卤反应研究——一种β-CF_3取代的α，β不饱和酮的合成法

在无引发剂或紫外光照的情况下，烯胺能与CF_3CXYZ(X,Y,Z=Cl, Br)进行自发 的反应，得么以Z-式异构体为主的 β-CF_3取代的 α，β不饱和酮，产率为50%左 右。反应可能是经由电子转移引发的自由基型机理进行的。     

Chiral ligand-controlled catalytic asymmetric epoxidation of α,β-unsaturated carbonyl compounds with peroxide

Asymmetric epoxidation reaction of α,β-unsaturated carbonyl compounds with alkylperoxide was catalyzed by an external chiral tridentate aminodiether-lithium peroxide giving epoxides with good enantiomeric excess. Slow addition of alkylhydroperoxide was beneficial for a catalytic asymmetric reaction. Lone pair electron-differentiating coordination of a carbonyl oxygen to lithium is another critical factor for high enantioselectivity.     

Selective Reduction of Aryl Substituted Chalcones with Zn/Ammonium/Ethanol/Water

The selective reduction of carbon-carbon double bonds of α, β-unsaturated carbonyl compounds has attracted great interest in organic synthesis. Of many reductive systems described in the literature, transitional metal such as Pd, Rh, Pt, Ni, Cu, Ir and their complexes are usually utilized as catalysts, hydrides of Sn, Se, Te, B and sodium dithionite have been developed to catalyze selective reduction of α, β-unsaturated carbonyl compounds.     

1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane: An efficient and high oxygen content oxidant in various oxidative reactions

Several oxidative approaches namely thiocyanation of aromatic compounds, epoxidation of alkenes, amidation of aromatic aldehydes, epoxidation of α, β-unsaturated ketones, oxidation of sulfides to sulfoxides and sulfones, bayer-villeger reaction, bromination and iodation of aniline and phenol derivatives oxidative esterification, oxidation of pyridines and oxidation of secondary, allylic and benzyllic alcohols were carried out using 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane as the potential solid oxidant which can be stored for several months without any loss in its activity. All of the procedures were accomplished via mild reaction conditions and the products were afforded in high yields and short reaction times.