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.
direct and effective transformation of α-amino ketones, acetamides, and esters to the corresponding α-diazo products under mild basic conditions has been developed. This one-step synthetic approach not only allows for generation of α-substituted-α-diazo carbonyl compounds from α-amino acidderivatives but also permits preparation of α-diazo dipeptides from N-terminal dipeptides (32 examples, up to 91%)
A new type of chiral pyridoxamines bearing an adjacent chiral stereocenter has been developed via multi-step synthesis. The pyridoxamines displayed catalytic activity in asymmetric transamination of α-keto acids to give a variety of optically active amino acids in 27–78% yields with 34–62% ee’s under very mildconditions. This work provides a synthetic strategy to construct newchiral pyridoxamines
Oleanolic acid and its derivatives: New inhibitor of protein tyrosine phosphatase 1B with cellular activities
作者:Yi-Nan Zhang、Wei Zhang、Di Hong、Lei Shi、Qiang Shen、Jing-Ya Li、Jia Li、Li-Hong Hu
DOI:10.1016/j.bmc.2008.07.080
日期:2008.9
Proteintyrosinephosphatase1B is a key factor in the negative regulation of insulin pathway and a promising target for treatment of diabetes and obesity. Herein, a series of competitive inhibitors were optimized from oleanolic acid, a natural triterpenoid identified against PTP1B by screening libraries of traditional Chinese medicinal herbs. Modifying at 3 and 28 positions, we obtained compound 13
Ligand-Enabled <i>meta</i>-Selective C–H Arylation of Nosyl-Protected Phenethylamines, Benzylamines, and 2-Aryl Anilines
作者:Qiuping Ding、Shengqing Ye、Guolin Cheng、Peng Wang、Marcus E. Farmer、Jin-Quan Yu
DOI:10.1021/jacs.6b11097
日期:2017.1.11
meta-selective C-H arylation of nosyl-protected phenethylamines and benzylamines is disclosed using a combination of norbornene and pyridine-based ligands. Subjecting nosyl protected 2-aryl anilines to this protocol led to meta-C-H arylation at the remote aryl ring. A diverse range of aryl iodides are tolerated in this reaction, along with select heteroaryl iodides. Select aryl bromides bearing ortho-coordinating