不对称Michael加成反应研究进展

随着有机小分子催化不对称有机合成反应的发展,人们设计出了大量的手性有机小分子催化剂并对于有机小分子催化的不对称Michael加成也进行了大量的研究。本文综述了近年来国内外不同研究小组对不对称Michael加成的研究进展,并对不同催化剂在不对称Michael加成反应中的应用进行了简单的评述。     

Michael加成反应的研究进展

综述了微波辐射、超声辐射、催化不对称合成以及固相反应等在Michael加成反应中的应用，总结了Michael加成反应的研究进展，并对今后的研究方向提出了建议。     

催化不对称氧杂Michael加成反应合成吲哚基醚类化合物

在乙酸存在下,经二苯基脯氨醇催化,成功地实现了不对称氧杂Michael加成反应,得到具有手性的吲哚基醚类化合物。该反应具有良好的收率及中等程度的对映体过量百分数(ee)。该方法为合成具有抵抗癌症的含有吲哚基的药物分子提供了一种新的途径。     

醛的不对称加成反应进展

综述了近几年来有关醛的不对称加成的报道。包括与有机金属化合物加成,与氰化物加成,与炔的加成,醛的烯丙基化,Dields—Alder反应以及手性冠醚在醛的不对称加成反应中的应用等。     

乙醛酸酯-烯不对称催化反应的研究进展

催化乙醛酸酯-烯反应(glyoxylate-ene reaction)合成具有光学活性的α-羟基酯需要运用手性催化剂。本文主要介绍了该类手性催化剂的研究进展。     

双官能团硫脲-胺催化剂催化不对称有机反应的研究进展

双官能团硫脲-胺催化剂因在不对称催化反应中表现出的高效、高对映选择性而受到广泛关注,已成功应用于催化各种不对称有机反应中,本文简述了双官能团硫脲-胺催化剂在Michael加成、1,2加成以及Michael-type串联反应中应用的研究进展。     

手性脯酰胺催化剂的合成及其在不对称Michael加成反应中的应用

本论文主要研究了L-脯氨酸衍生的手性脯酰胺催化剂的设计、合成及其在不对称Michael加成反应中的应用。我们以硝基烯和环己酮为底物,考察了催化剂1和2在不对称Michael加成反应的催化活性和立体选择性。结果表明,以二氯甲烷为溶剂,以化合物2为催化剂,以三氟乙酸为辅助试剂,于室温反应12小时,加成产物的收率可达81%,立体选择性为71%。     

手性脯酰胺催化剂的合成及其在不对称Michael加成反应中的应用

本论文主要研究了L-脯氨酸衍生的手性脯酰胺催化剂的设计、合成及其在不对称Michael加成反应中的应用。我们以硝基烯和环己酮为底物,考察了催化剂1和2在不对称Michael加成反应的催化活性和立体选择性。结果表明,以二氯甲烷为溶剂,以化合物2为催化剂,以三氟乙酸为辅助试剂,于室温反应12小时,加成产物的收率可达81%,立体选择性为71%。     

新型Michael加成反应催化剂研究进展?

Michael加成反应是指烯醇盐负离子与α,β-不饱和化合物的共轭加成反应,是最重要的有机合成反应之一,Michael加成反应催化剂研究是化学研究的热点.综述了近十年来新型Michael加成反应催化剂如新型的有机小分子催化剂、负载催化剂及其他特殊催化方法等的研究进展,着重探讨了新型催化剂的高效性和催化剂再利用,同时指出,开发催化Michael加成反应的高效环境友好型催化剂是今后研究的重点.     

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。     

不对称Reformatsky反应研究进展

介绍了近年来国内外不对称Reformatsky反应在有机合成中的应用。     

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.     

不对称Reformatsky反应的研究进展

综述了近年来不对称Reformatsky反应在有机合成中的应用。     

Highly Efficient Amine Organocatalysts Based on Bispidine for the Asymmetric Michael Addition of Ketones to Nitroolefins

A highly diastereoselective and enantioselective Michael addition of cyclohexanone, acetone and other ketones to nitroolefins was developed by the use of an amine organocatalyst based on bispidine. Additionally, a theoretical study of transition structures revealed that this bispidine‐based primary‐secondary amine catalyst could serve through an enamine intermediate and H‐bond interaction, which was important for the reactivity and selectivity of this reaction.     

Applications of Michael addition chemistry in coatings technology

Since the first filings of patent applications on the use of the Michael addition as crosslinking reaction for coatings around 1984, a lot of research work has been carried out on its application in practical systems. Initial work on the development of coatings for aircraft, car refinishing and timber showed that, especially with urethane acrylate/malonate polyester combinations, the expected high level of durability could be achieved. Further developments in the field of high solids coatings revealed inhibition problems however. They were caused by the interaction of the strong bases, used as the catalysts for the Michael reaction, with acidic ingredients from the substrate and with carbon dioxide from the atmosphere. In principle the problem can be solved by using higher doses of catalyst, but the potlife is too short for general use then. Temporary blocking of the catalysts with an alcohol or with carboxylic acids was investigated as a way to achieve an acceptable potlife. The use of catalysts blocked with carboxylic acids, deblockable with heat or UV light, is a good solution for industrial coatings. Blocking with an alcohol helps to solve the problem of inhibition by carbon dioxide but not the problem of inhibition by the acidic sites in the substrate.     

Novel Easily Recyclable Bifunctional Phosphonic Acid Carrying Tripeptides for the Stereoselective Michael Addition of Aldehydes with Nitroalkenes

A novel bifunctional organocatalyst library combining both aminocatalysis and phosphonic acid activation was used for the first time as an efficient tool for the stereoselective Michael addition of aldehydes with several aromatic nitroalkenes with good selectivities up to 95:5 dr and 93:7 er. Due to their high water solubility, the catalysts were easily recyclable and could be reused over several cycles without any significant loss of selectivity.

     

Asymmetric One‐Pot Synthesis of 1,4‐Dihydroquinolines via an Organocatalytic Aza‐Michael/Michael Cascade Strategy

A synthetic method for the construction of fully substituted enantioenriched 1,4‐dihydroquinolines using an organocatalytic aza‐Michael/Michael cascade reaction has been developed. The asymmetric reaction of 2‐(tosylamino)phenyl α,β‐unsaturated ketones with alkynyl aldehydes, promoted by diphenylprolinol O‐TMS ether as an organocatalyst, generated chiral 1,4‐dihydroquinolines in good to high yields with excellent enantioselectivities (up to 97 % ee).

     

Na_3PO_4催化查尔酮和环己酮的迈克尔反应研究

温和条件下,以磷酸钠催化查尔酮和环己酮的迈克尔加成反应,考察了反应物料配比、催化剂用量、反应溶剂、反应时间等对反应的影响。结果表明,最佳工艺条件为:查尔酮和环己酮的摩尔比为1∶1.53,催化剂用量0.31 g,二甲亚砜为溶剂,反应时间3 h,此条件下,收率可达82.1%。该法具有反应条件温和、催化剂用量小、无污染、后处理简单等优点。     

Asymmetric Synthesis of 2,3,4‐Trisubstituted Functionalised Tetrahydrofurans via an Organocatalytic Michael Addition as Key Step

The organocatalytic Michael addition of various aldehydes to (2E,4E)‐ethyl 5‐nitropenta‐2,4‐dienoate has been achieved under the catalysis of diphenylprolinol trimethylsilyl ether furnishing the products in good to excellent yields (61–94%) and high stereoselectivities (dr up to >98:2, ee=97 to >99%). Starting from these Michael adducts, 2,3,4‐trisubstituted functionalized tetrahydrofurans are available in two steps by reduction of the aldehyde followed by an intramolecular oxa‐Michael addition in good yields (54–76%) and stereoselectivities (dr up to >95:5, ee=97 to >99%).