Unexpected Catalyst for Wittig-Type and Dehalogenation Reactions
作者:Zheng-Zheng Huang、Yong Tang
DOI:10.1021/jo025693b
日期:2002.7.1
A novel catalyst 2 for Wittig-type and dehalogenation reactions was developed. In the presence of triphenyl phosphite, a wide variety of aldehydes could react with alpha-bromoacetates to afford alpha,beta-unsaturated esters or ketones in high yields with excellent E-stereoselectivity when 1-2 mol % of compound 2 was used. Compound 2 was also an effective catalyst for reductive dehalogenation of alpha-bromocarbonyl
Catalyzed Claisen–Schmidt reaction by protonated aluminate mesoporous silica nanomaterial focused on the (E)-chalcone synthesis as a biologically active compound
作者:Mohammad Reza Sazegar、Shaya Mahmoudian、Ali Mahmoudi、Sugeng Triwahyono、Aishah Abdul Jalil、Rino R. Mukti、Nur H. Nazirah Kamarudin、Monir K. Ghoreishi
DOI:10.1039/c5ra23435b
日期:——
catalyzed the synthesis of (E)-chalcones through the Claisen–Schmidt reaction. Chalcone derivatives have been applied as biologically active compounds with anti-cancer, anti-inflammatory and diuretic pharmacological activities. The products were obtained via reactions on the protonic acid sites of HAlMSN. The significant advantages of this reaction are high yield, easy work up, short reaction time and also
介孔二氧化硅结构(MSN)是使用溶胶-凝胶法合成的,然后进行铝接枝和质子化,然后表示为HAlMSN(Si / Al = 18.9)。N 2的物理吸附证实了具有3.38 nm孔径的中孔结构。27 Al NMR显示存在骨架和骨架外的铝结构,这导致形成很强的Lewis和Brønsted酸性位。HAlMSN通过Claisen-Schmidt反应催化(E)-查耳酮的合成。查耳酮衍生物已被用作具有抗癌,抗炎和利尿药理活性的生物活性化合物。产品是通过以下途径获得的HAlMSN质子酸位点上的反应 该反应的显着优点是产率高,易于后处理,反应时间短以及与各种有机溶剂的相容性。得到的产物在298 K下具有97%的优异转化率。结果表明,与吸电子取代基相比,给电子取代基表现出更高的转化率。通过将其重复使用五次以生产(E)-查耳酮来研究催化剂的稳定性,并且其催化活性仅略微降低。最高产品(E在苯甲醛/苯乙酮的摩尔比为1
Transition-Metal-Free Catalytic Formal Hydroacylation of Terminal Alkynes
Although hydroacylation is a very useful reaction for producing ketonesfromaldehydes with 100% atom efficiency, classical Rh-catalyzed hydroacylation presents several problems, including the need for transition metal catalysts, unwanted decarbonylation of aldehydes, and difficulty in regioselectivity control. However, formal hydroacylation utilizing the nucleophilicity of terminal alkynes can avoid
Indole containing compounds have acquired conspicuous significance due to their wide spectrum of biological activities. Synthesis of a series of enantiomerically pure indole derivatives 3a-r via Friedel–Crafts alkylation of indole 1 with enones 2a-r were described here. The products were isolated in a moderate to excellent yields (upto 89%) with excellent enantioselectivities (upto 99.9% ee). These
Novel diastereoselective synthesis of spiropyrrolidine-oxindole derivatives as anti-breast cancer agents
作者:Atul Kumar、Garima Gupta、Suman Srivastava、Ajay Kumar Bishnoi、Ruchi Saxena、Ruchir Kant、Ranjana S. Khanna、Prakas R. Maulik、Anila Dwivedi
DOI:10.1039/c3ra21595d
日期:——
A novel class of diastereoselective spiropyrrolidine-oxindole derivatives were synthesized fromisatin, 2-phenylthiazolidine-4-carboxylic acid and chalcone in a one-pot multicomponent reaction via1,3-dipolarcycloaddition. The advantages of this methodology are the mild reaction conditions, high diastereoselectivity and high yield. These derivatives exhibited promising anti-cancer activity against