Piperodione (3), a secondary metabolite previously isolated from the Javanese pepper plant Piper retrofractum in 0.0002% isolated yield was synthesized in a convergent strategy utilizing a Mannich and a Stetter reaction. An over-all yield of 76% could be achieved. Several analogs were prepared by this synthetic sequence. None of the compounds showed a significant cytotoxicity for human tumor cells (photometric sulforhodamine B assay). (C) 2014 Elsevier Ltd. All rights reserved.
Catalytic asymmetric oxidation of 1H-benzimidazolyl pyridinylmethyl sulfides with cumene hydroperoxide catalyzed by a titanium complex with (S,S)-N,N′-dibenzyl tartramide ligand
摘要:
A chiral titanium complex, formed in situ from Ti(Oi-Pr)(4), (S,S)-N,N'-dibenzyl tartramide and water was found to serve as an efficient catalyst for the asymmetric oxidations of 1H-benzimidazolyl pyridinylmethyl sulfides with cumene hydroperoxide (CHP) in the absence of a base. Several proton pump inhibitors (PPIs), such as esomeprazole, lansoprazole, rabeprazole and pantoprazole were obtained in high yield (up to 92%) and excellent enantiomeric excess (up to 96%). (C) 2012 Elsevier Ltd. All rights reserved.
Synthesis, characterization, and coordination chemistry of two new tartaric acid-derived bis(phosphite) ligands
作者:Samuel B. Owens、Gary M. Gray
DOI:10.1016/j.jorganchem.2008.10.003
日期:2008.12
also been determined. The X-ray crystal structures indicate that the conformation of the seven-membered chelatering varies depending on the substituents on the tartrate backbone. However, the conformations of the seven-membered ringsdo not change when the metal center is changed or when the coordination environment around the metal center is changed.
具有酒石酸衍生主链的两个手性双(亚磷酸酯)配体的合成:1(酒石酸二甲酯)和2(二戊二烯酒石酰胺),三种1:顺式-Mo(CO)4(1),顺式-PtCl的配合物2(1),和顺式-PdCl 2(1)和两个配合2:顺式-Mo(CO)4(2)和顺式-PdCl 2(2)中有所描述。每个配体和复合物都具有以下特征:1 H,13 C和31 P NMR光谱和配位31 P NMR化学位移已与相关配体配合物的观察值进行了比较。还已经确定了每种金属配合物的X射线晶体结构。X射线晶体结构表明七元螯合环的构象根据酒石酸骨架上的取代基而变化。但是,当改变金属中心或改变金属中心周围的配位环境时,七元环的构型不会改变。
Piperodione (3), a secondary metabolite previously isolated from the Javanese pepper plant Piper retrofractum in 0.0002% isolated yield was synthesized in a convergent strategy utilizing a Mannich and a Stetter reaction. An over-all yield of 76% could be achieved. Several analogs were prepared by this synthetic sequence. None of the compounds showed a significant cytotoxicity for human tumor cells (photometric sulforhodamine B assay). (C) 2014 Elsevier Ltd. All rights reserved.
First asymmetric synthesis of enantiomerically pure (1R,2S)-(-)-(1,2-epoxypropyl)phosphonic acid (fosfomycin)