由α-羰基烯酮式二硫代缩醛化合物合成中间体的方法

以乙酰乙酸甲酯、乙酰乙酸乙酯为原料 ,使用二硫化碳以及不同的卤代烃 ,合成了一系列α 羰基烯酮式二硫代缩醛化合物 ,再以这些化合物为底物与Reformatsky试剂反应 ,合成了两种重要的有机合成活性中间体     

无气味和有效的β-羰基硫醚的合成

以易制备和无气味的3-（二乙硫/苄硫基）亚甲基-2,4-戊二酮1作乙硫醇和苄硫醇替代试剂,进行了环保和无气味的β-羰基硫醚的合成研究。在甲醇介质中,氯化乙酰存在下,1发生分解反应,释放出乙硫醇或苄硫醇,然后与α,β-不饱和酮2进行硫杂迈克尔加成反应,高产率生成β-羰基硫醚,反应过程无恶臭气味。     

代硫醇试剂与α，β-不饱和酮的Michael加成反应

用4 ,4 - 二烷硫基- 3 - 烯- 2 - 丁酮(1a) 和4 ,4 - 二苯硫基- 3 - 烯- 2 - 丁酮(1b)作为无气味硫醇替代试剂,进行了硫代Michael加成反应研究.以甲醇为溶剂,加入乙酰氯,经酸催化1a和1b混合产生硫醇,与α,β- 不饱和酮(2) 发生共轭加成反应,得到相应的高收率的硫杂Michael加成产物(3) ,并对其反应机理进行了探讨.     

近年来ɑ-羰基二硫缩烯酮类化合物的Vilsmeier反应

在有机合成中,Vilsmeier反应一直是广泛应用的一类有机反应,其中Vilsmeier试剂是取代酰胺和卤化物形成的混合物。在Vilsmeier试剂的作用下,反应物发生甲酰化、氯化甲酰化、芳香化、重排、脱水、环化等反应,制备了大量在农药、染料和医药方面具有重要应用价值的化合物。本文主要介绍了ɑ-羰基二硫缩烯酮的Vilsmeier反应。     

1-(1,3-二硫戊环/二噻烷)-2-亚甲基-1-芳偶氮基丙酮类化合物的合成研究

研究了二硫缩烯酮类化合物α-碳原子上的反应,以α-羰基/羧基二硫缩烯酮与芳基重氮盐作用,以较高产率获得了系列1-(1,3-二硫戊环/二噻烷)-2-亚甲基-1-芳偶氮基丙酮类化合物。该反应条件温和,操作方法简单,同时对其反应机理进行了初步探讨。     

2-(1,3-二烷硫基)亚甲基-3-羰基丁酰胺作为代硫醇试剂的缩硫醛化学反应研究

探讨了以2-(1,3-二烷硫基)亚甲基-3-羰基丁酰胺为代硫醇试剂,苯甲氯为催化剂,乙醇为溶剂的缩硫醛化反应。结果表明,该代硫醇试剂能快速与芳香醛以较高产率生成缩硫醛类化合物,研究其合成方法,对各化合物进行了结构表征,对其反应机理进行了初步探讨。     

硫酸铝催化柠檬醛和1，2-丙二醇的缩醛化反应

本文研究了硫酸铝催化柠檬醛和1，2-丙二醇的缩醛化反应，考察醇酸用量比、催化剂用量、反应温度及时间对反应结果的影响。当柠檬醛和1，2-丙二醇用量均为0．10mol，A12(SO4)5．18H2O10g／mol，加入18ml环已烷，在94～102℃温度范围内回流分水2．5h，获得缩醛的产率可为85．5％，且使用该催化剂具有易分离、操作简单、产品质量好的特点。     

乙醛正丁硫醇缩硫醛的合成

以乙缩醛 ( 0 .75mol)和正丁硫醇 ( 0 .5mol)为原料 ,溴化镁 ( 73g)为一次性催化剂 ,在乙醚( 1 0 0mL)中 ,室温条件下反应 32h ,经红外光谱、色谱、质谱、元素分析以及核磁共振谱检测 ,确证了产物为乙醛正丁硫醇缩硫醛 ,粗产率为 68%。用硅胶作柱层析固定相 ,V(四氯化碳 )∶V(二氯甲烷 ) =1 0∶1作为展开剂和洗脱剂提纯产品 ,质量分数为 95%。     

5,6-二氢-6-烷基(芳基)-2H-吡喃-2,4-二酮的二硫缩醛化合物的合成及生物活性研究

采用5,6-二氢-6-烷基(芳基)-2H-吡喃-2,4-二酮在碱性条件下与二硫化碳和卤代烃进行缩合反应,合成了一系列吡喃酮的二硫缩醛。其结构经1HNMR和元素分析证实。生物活性初步测定表明,该类化合物具有一定的杀菌和除草的活性。     

净味乳胶漆防腐剂的选择研究

研究了净味乳胶漆用乳液与防腐剂的搭配。讨论了防腐剂的结构及杀菌原理。通过实验,对常用防腐剂在净味乳胶漆中的杀菌性能作了评估。     

聚乙烯醇缩醛的应用

本文对聚乙烯醇缩醛（聚乙烯醇缩甲醛、缩乙醛、缩甲乙醛、缩丁醛等）在胶粘剂（结构胶粘剂、热熔胶、密封胶、水分散体及安全玻璃、电子陶瓷铸模添加剂、印刷电路、可燃弹壳、制动蹄、研磨料用粘合剂）与涂饰剂（蚀洗底漆、表面涂层、漆包漆及在纸张纺织品、静电复印、墨水、染料）中的应用作了介绍。     

合成缩醛(酮)的催化剂研究进展

综述了固体超强酸、杂多酸、固载杂多酸、脱铝超稳沸石、树脂、分子筛、铌酸、漆酚衍生物、维生素C、碘、硫酸盐、氯化物、蒙脱土等40多种催化剂催化合成缩醛(酮)的方法和反应条件。评述了各类催化剂的催化性能、特点、能否重复使用等内容。结果表明:固体超强酸、固载杂多酸、HY型分子筛、脱铝超稳沸石、硫酸铜、高分子载体氯化物等几种环境友好催化剂是合成缩醛(酮)的优良催化剂。     

Ruthenium(III) Chloride‐Catalyzed Thioacetalization of Carbonyl Compounds: Scope,Selectivity, and Limitations

A variety of carbonyl compounds can be easily and rapidly converted to the corresponding cyclic and acylic dithioacetals in the presence of a catalytic amount of ruthenium chloride in acetonitrile at room temperature. Some of the major advantages of this protocol are high chemoselectivity, operational simplicity, very short reaction times, high yields, and also compatibility with other protecting groups.     

Formation of Acetals under Rhodium‐Catalyzed Hydroformylation Conditions in Alcohols

Hydroformylation of terminal alkenes in alcohol solvents leads to the selective formation of the corresponding acetals. The Xantphos ligand gave the best results as well as acetal selectivities higher than 99% and linear/branched ratios of up to 52 were obtained. The scope of the reaction was studied. Acetals were found to be unreactive under hydroaminomethylation conditions.     

A Catalytic Deprotection of S,S‐, S,O‐ and O,O‐Acetals Using Bi(NO3)3⋅5 H2O under Air

S,S‐Acetals are smoothly deprotected with air in the presence of a catalytic amount of Bi(NO₃)₃⋅5 H₂O (1–50 mol %) under ambient conditions to regenerate the original carbonyl compounds in good to excellent yield. This mild, simple, and environmentally benign system is successfully applied to the deprotection of S,O‐ and O,O‐acetals and is compatible with various functional groups. From the mechanistic study of the reaction, the catalytic cycle is considered to be composed of the following four steps: (1) the nitrososulfonium ion of the S,S‐acetal is formed by attack of nitrosonium ion (NO ⁺) generated from Bi(NO₃)₃⋅5 H₂O through the equilibrium with NO₂, (2) the nitrososulfonium ion is hydrolyzed to afford the hemithioacetal and thionitrite, (3) the hemithioacetal collapses to the original carbonyl compound and thiol, which is oxidized by NO ⁺ to give disulfide and NO via thionitrite, and (4) the NO captures molecular oxygen from air to regenerate NO₂.     

An Alternative Approach to Direct Aldol Reaction Based on Gold‐Catalyzed Methoxyl Transfer

A mild and catalyzed alternative to the direct aldol reaction has been developed based on the gold‐catalyzed methoxy group transfer from dimethyl acetals to terminal alkynes. Due to the simultaneous activation of the acetals, this aldol approach is only functional for acetals but not aldehydes. A ligand effect from the gold complex has also been observed.     

Enzymatic Transformations 62. Preparative Scale Synthesis of Enantiopure Glycidyl Acetals using an Aspergillus niger Epoxide Hydrolase‐Catalysed Kinetic Resolution

The hydrolytic kinetic resolution of five glycidaldehyde acetal derivatives was examined using the recombinant Aspergillus niger epoxide hydrolase as biocatalyst. This could successfully be performed, at room temperature, using solely demineralised water as solvent and following a two‐phase methodology allowing us to operate at a global substrate concentration as high as 200 g/L in the reactor. The observed E values were shown to be modest to excellent, depending on the structure of the acetal moiety, indicating that it is possible to achieve this resolution very efficiently just by choosing the right substituents. Both the unreacted (R)‐epoxide and the formed (S)‐diol could thus be obtained in good to excellent ee (ee>99 % for the epoxide). For the best substrates, the reaction could be performed within a few hours by using a biocatalyst over substrate molecular ratio of about 9 to 10×10⁻⁴ mol %. The turnover frequency (TOF) as well as the total turnover number (TON) of the enzyme proved to be excellent as compared to chemical catalysts – reaching respectively values in the order of 6×10² mol sub/mol enz/min and 6×10⁴ mol sub/mol enz. The space‐time yield of the best (two‐phase) reactor could thus reach a value as high as 56 g/L/hour. As a demonstration experiment, a 50‐g scale resolution of glycidaldehyde 2,2‐dimethyltrimethylene acetal was performed.