Synthesis and bioactivity of novel 3-(1-hydroxyethylidene)-5-substituted-pyrrolidine-2,4-dione derivatives
摘要:
Ten novel 5-substituted derivatives of 3-(1-hydroxyethylidene)pyrrolidine-2,4-dione were synthesized. The compounds were confirmed by IR, H-1 NMR, MS and elemental analysis. The bioassay indicated that these compounds showed noticeable herbicidal activities, and compounds 6f and 6j exhibited excellent inhibitory activities against the stalk of Echinochloa crusgalli, with EC50 values of 94.4 and 72.7 mg/L, respectively. (C) 2012 Chun Long Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Synthesis and bioactivity of novel 3-(1-hydroxyethylidene)-5-substituted-pyrrolidine-2,4-dione derivatives
摘要:
Ten novel 5-substituted derivatives of 3-(1-hydroxyethylidene)pyrrolidine-2,4-dione were synthesized. The compounds were confirmed by IR, H-1 NMR, MS and elemental analysis. The bioassay indicated that these compounds showed noticeable herbicidal activities, and compounds 6f and 6j exhibited excellent inhibitory activities against the stalk of Echinochloa crusgalli, with EC50 values of 94.4 and 72.7 mg/L, respectively. (C) 2012 Chun Long Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
4-addition and [3 + 2] cycloaddition reactions using chiral calcium species prepared from calcium isopropoxide and chiral bisoxazoline ligands have been developed. Glycine Schiff bases reacted with acrylic esters to afford 1,4-addition products, glutamic acid derivatives, in high yields with high enantioselectivities. During the investigation of the 1,4-addition reactions, we unexpectedly found that a [3
[Object] To provide a medicine useful for treatment and prevention of hyperlipidemia, further for the treatment and prevention of cholestasis-accompanying hepatopathy, particularly primary biliary cirrhosis and primary sclerosing cholangitis, and for the treatment and prevention of obesity and fatty liver.
[Means] A benzothiazepine compound represented by the following formula (1), having a thioamide bond and a quaternary ammonium substituent.
A Facile Cu(I)/BINAP-Catalyzed Asymmetric Approach to Functionalized Pyroglutamate Derivatives Bearing a Unique Quaternary Stereogenic Center
作者:Huai-Long Teng、Fei-Long Luo、Hai-Yan Tao、Chun-Jiang Wang
DOI:10.1021/ol202326j
日期:2011.10.21
pyroglutamate derivatives bearing a unique quaternary stereogenic center has been developed via Cu(I)/BINAP-catalyzed tandem Michael addition–elimination of α-substituted aldimino esters with Morita–Baylis–Hillman (MBH) carbonates followed by a deprotection/lactamization protocol, which performs well over a broad scope of substrates and provides biologically active pyroglutamate derivatives in good yields
Silver(I)-Catalyzed Atroposelective Desymmetrization of <i>N</i>-Arylmaleimide via 1,3-Dipolar Cycloaddition of Azomethine Ylides: Access to Octahydropyrrolo[3,4-<i>c</i>]pyrrole Derivatives
作者:Hua-Chao Liu、Hai-Yan Tao、Hengjiang Cong、Chun-Jiang Wang
DOI:10.1021/acs.joc.6b00396
日期:2016.5.6
has been established successfully, affording a facileaccess to a series of biologically important and enantioenriched octahydropyrrolo[3,4-c]pyrrole derivatives in generally high yields (up to 99%) with excellent levels of diastereo-/enantioselectivities (up to 99% ee, >20:1 dr). Subsequent transformations led to fascinating 2H-pyrrole and polysubstituted pyrrole compounds without loss of stereoselectivity
已经成功地建立了通过原位生成的偶氮甲亚胺的1,3-偶极环加成反应的N-(2-叔丁基苯基)马来酰亚胺的高效Ag(I)催化的对位选择性脱对称,为人们提供了一系列重要的生物学上的便捷途径和对映体富集的八氢吡咯并[3,4- c ]吡咯衍生物,通常收率高(高达99%),非对映/对映选择性极好(ee高达99%,> 20:1 dr)。随后的转化导致令人着迷的2 H-吡咯和多取代的吡咯化合物,而不会失去立体选择性。生成的手性轴的绝对构型已明确标识为(M)通过单晶X射线衍射分析。此外,基于全面的实验结果和一种环加合物的绝对构型,立体选择性的起源被认为归因于手性配体和叔丁基的庞大的PPh 2基团造成的空间拥挤。N-(2-叔丁基苯基)马来酰亚胺的基团。手性配体的NH 2基团与N-(2-叔丁基苯基)马来酰亚胺的羰基之一之间可能的氢键相互作用被认为有助于稳定过渡态。
Nickel/Copper‐Cocatalyzed Asymmetric Benzylation of Aldimine Esters for the Enantioselective Synthesis of α‐Quaternary Amino Acids
The first Ni/Cu cocatalyzed asymmetric benzylation of aldimine esters has been developed. DFT calculations revealed that the strong electrophilicity of the η3-benzylnickel intermediate enabled the reaction to proceed smoothly under base-free conditions. The method was applied to the synthesis of BIRT-377 analogues, the key intermediate of PD154075 and CI-988.