相转移催化合成亚苄基丙酮

相转移催化合成亚苄基丙酮丁养军，刘永军（曲阜师范大学化学系，曲阜２７３１６５）亚辛基丙酮是一个用途很广泛的有机化名物，尤其是在香料工业和电镀工业中［‘·’‘。它具有强香豌豆型香气，用于调配香豌豆系列香粽和果香食用香精，亦用于橙花和风信子等香基它本身是...     

2-硫代-4-噻唑酮与查尔酮的无溶剂Michael加成反应

以查尔酮和2-硫代-4-噻唑酮为原料,在NaOH存在下无溶剂室温研磨反应,非常方便合成了系列未见文献报道的Michael加成产物.该方法具有反应条件温和、操作简单和产率较高等优点,并通过IR、HNMR、MS和元素分析确证产物的结构.     

TSA催化合成二亚苄基山梨醇的研究

本文研究了利用多种催化剂在不同条件下合成１,３;２,４－二亚苄基山梨醇。结果表明：采用ＴＳＡ为催化剂,当山梨醇：苯甲醛＝１：２．４（物质的量比）,催化剂、甲醇、环己烷用量分别为反应基因物的４．０％、２４７％、５８４％,反应温度７５℃,反应时间５ｈ,产率可高达９６．５％。     

由苯乙酸合成二苄基酮的研究

本文介绍了以二氧化锰／三氧化铝力催化剂，由苯乙酸合成二苄基酮的方法，苯乙酸的转化率为９９％，催化剂对二苄基酮的选择性为８１％。     

KF／Al2O3催化下的Michael加成反应

Ｍｉｃｈａｅｌ加成反应是形成碳—碳键的重要方法之一,该反应一般在强碱（如醇钠）作用下进行,反应条件比较苛刻。而ＫＦ／Ａｌ２Ｏ３作为一种碱性催化剂,与其他催化剂相比有反应条件温和,催化剂活性高,选择性强,后处理简单,产率高等优点,在有机合成上获得了广泛...     

二苄基酮一步合成新工艺

在反应容器中,同时滴加苯乙酰氯及苄基溴的甲苯溶液于乙醚中,一步合成二苄基酮,收率达84％。     

硫脲催化剂催化硝基烯烃的Michael加成反应的研究进展

靠氢键作用结合的硫脲催化剂因其良好的催化活性而受到广泛关注,被应用于各种不对称Michael加成反应中。本文主要介绍了硫脲催化剂在催化硝基烯烃的Michael加成反应中的研究现状,并对其应用前景及发展趋势进行了展望。     

手性伯胺催化剂催化Michael加成反应的研究进展

在许多不对称有机反应中,手性伯胺催化剂已被证实是一种高效的催化剂,被广泛应用于各种Michael加成反应中。Michel加成是有机合成中构建碳一碳键的重要反应之一,本文综述了近年来手性伯胺催化剂在Michael加成反应中的研究新进展。     

二苄基酮一步合成新工艺

在反应容器中，同时滴加苯乙酰氯及苄基溴的甲苯溶液于乙醚中，一步合成二苄基酮，收率达８４％。     

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.     

磷酸锌钠负载KF催化Michael加成反应

以磷酸锌钠负载KF为催化剂,催化乙酰乙酸乙酯与丙烯腈进行Michael加成反应.用熔点测定仪、IR、GCMS、1H-NMR表征了加成产物,产物的总产率为81.8%.实验结果表明,KF/NaZnPO4是一种催化α,β不饱和共轭体系和含有活泼亚甲基化合物反应的良好催化剂,该反应可在温和的条件下高效地进行,产品产率高,纯度好,操作和后处理简单方便.     

Michael Addition of Ketones and Aldehydes to Maleimides Catalyzed by Modularly Designed Organocatalysts

Modularly designed organocatalysts (MDOs) formed in situ from the self‐assembly of primary α‐amino acids and Cinchona alkaloid thioureas were found to be excellent catalysts for the stereoselective Michael addition of enolizable ketones and aldehydes to maleimides. Using an MDO formed from quinidine thiourea and L ‐2‐chlorophenylglycine, the corresponding Michael addition products, 3‐substituted succinimides, may be obtained in excellent yields and high enantio‐ and diastereoselectivities.     

Prolylprolinol‐Catalyzed Asymmetric Michael Addition of Aliphatic Aldehydes to Nitroalkenes

Several novel prolylprolinol catalysts have been designed and synthesized. This type of compound showed high catalytic efficiency on promoting the direct addition of unmodified aldehydes to nitroalkenes. Among the catalysts surveyed, the least bulky member ( 8d ) exhibited the best performance on both efficiency and stereoselectivity, providing the products with up to 97% ee value with 1.5–5 mol% catalyst loading. Additionally, computational studies of the transition state have been conducted to explain the high diastereo‐ and enantioselectivity.     

A Chiral Functionalized Salt‐Catalyzed Asymmetric Michael Addition of Ketones to Nitroolefins

The chiral functionalized salt catalysis, which differs from the known enzyme‐ and transition metal‐based methods, has been successfully developed to carry out the Michael addition of ketones to nitroolefins. Chiral anion salt (type I ), chiral cation salt (type II ), or chiral anion‐chiral cation salt (type III ) could be expected to be remarkably effective catalysts and afford the corresponding chemically and optically pure Michael addition adducts. A primary amine group activating the ketone during salt catalysis was their obvious and common property. Based on preliminary experimental investigations and previous reports on primary amine catalysis, a reaction pathway via imine, enamine, iminium ion to imine was proposed.     

Enantiocomplementary Michael Additions of Acetaldehyde to Aliphatic Nitroalkenes Catalyzed by Proline-Based Carboligases

The blockbuster drug Pregabalin is widely prescribed for the treatment of painful diabetic neuropathy. Given the continuous epidemic growth of diabetes, the development of sustainable synthesis routes for Pregabalin and structurally related pharmaceutically active γ-aminobutyric acid (GABA) derivatives is of high interest. Enantioenriched γ-nitroaldehydes are versatile synthons for the production of GABA derivatives, which can be prepared through a Michael-type addition of acetaldehyde to α,β-unsaturated nitroalkenes. Here we report that tailored variants of the promiscuous enzyme 4-oxalocrotonate tautomerase (4-OT) can accept diverse aliphatic α,β-unsaturated nitroalkenes as substrates for acetaldehyde addition. Highly enantioenriched aliphatic (R)- and (S)-γ-nitroaldehydes were obtained in good yields using two enantiocomplementary 4-OT variants. Our results underscore the synthetic potential of 4-OT for the preparation of structurally diverse synthons for bioactive analogues of Pregabalin.     

纳米二氧化硅催化剂催化Michael加成反应

脱水活化后的纳米二氧化硅颗粒能有效催化Michael加成反应,研究了不同温度及六甲基二硅氮烷(HMDS)处理改变二氧化硅表面性质后催化剂的催化性能改变。结果表明,随着热处理温度的升高,二氧化硅催化活性降低;HMDS能够覆盖其表面的单独硅羟基,从而降低二氧化硅催化活性。研究表明,二氧化硅表面的硅羟基是催化活性中心,催化活性与硅羟基浓度相关。不同溶剂对反应活性影响明显,DMF为反应的最佳溶剂,反应收率最高可达71%。     

Organocatalytic Enantioselective Sulfur‐Michael Addition of Thioacetic Acid to Arylmethylidenemalonates

An organocatalytic enantioselective sulfur‐Michael addition of thioacetic acid to arylmethylidenemalonates was developed with high yields and up to 97% enantiomeric excess. Both enantiomers of the products were accessible with two different organocatalysts. The current method provides the first, practical, and convenient preparation of enantiomerically enriched acetylthiomethylmalonate derivatives.

     

Iron‐Catalyzed Michael Addition of Ketones to Polar Olefins

The base metal complex tetrabutylammonium nitrosyltricarbonylferrate {Bu₄N[Fe(CO)₃(NO)] (TBA[Fe])} – catalyzes the conjugate addition of ketones to polar olefins. The reaction is applicable to a wide range of substrates leading to interesting building blocks for organic synthesis. Clear indications for an acid‐base type rather than a C−H activation pathway exist.