Efficient and convenient epoxidation of alkenes to epoxides with H2O2 catalyzed by Co(OAc)2 in ionic liquid [C12py][PF6]
作者:Yu-Lin Hu、Yi-Wen Liu、De-Jiang Li
DOI:10.1007/s13738-015-0695-8
日期:2015.12
A simple, efficient, and eco-friendly procedure for the epoxidation of alkenes to epoxides with H2O2 catalyzed by Co(OAc)2 in ionic liquid [C12py][PF6] has been developed. The reactions were carried out with alkene, Co(OAc)2 (0.1 mmol), [C12py][PF6] (10 mL), and H2O2 (30 %, 11 mmol) at room temperature for 2–6 h. This atom-economical protocol affords the target products in good to high yields (88–98 %). The products can be separated by a simple extraction with organic solvent, and the catalytic system can be recycled and reused without loss of catalytic activity. A simple, efficient, and eco-friendly procedure for the epoxidation of alkenes to epoxides with H2O2 catalyzed by Co(OAc)2 in ionic liquid [C12py][PF6] has been developed.
Ruthenium clay catalyzed chemoselective hydrogenation of unsaturated esters, epoxides, sulfones and phosphonates
作者:Raluca Aldea、Howard Alper
DOI:10.1016/s0022-328x(97)00493-2
日期:1998.1
Ru-clays were prepared using montmorillonite–PPh2 or montmorillonite–bpy and RuCl3·H2O. The clays obtained were found to be effective catalysts for the reduction of unsaturatedesters, epoxides, sulfones and phosphonates.
Separation and Identification of Volatile Components in the Fermentation Broth of Trichoderma atroviride by Solid-Phase Extraction and Gas Chromatography--Mass Spectrometry
作者:A. Keszler、E. Forgacs、L. Kotai、J. A. Vizcaino、E. Monte、I. Garcia-Acha
DOI:10.1093/chromsci/38.10.421
日期:2000.10.1
A preseparated fermentation broth of Trichoderma atroviride strain 11 is analyzed by gas chromatography followed by mass-spectral detection using a FinniganMAT GCQ apparatus. After preseparation in a C18 and a silica gel column, nineteen pyrone and dioxolane derivatives and two aliphatic esters are obtained, respectively. Among these, the four dioxolane derivatives have not been identified previously
通过气相色谱分析随后分离的阿魏木霉菌株11的发酵肉汤,然后使用Finnigan MAT GCQ仪器进行质谱检测。在C18和硅胶柱中进行预分离后,分别获得十九个吡喃酮和二氧戊环衍生物以及两种脂族酯。其中,四种二氧戊环衍生物先前尚未鉴定。发现主要成分为5,5'-二甲基-2H-吡喃-2-on。用于确定保留时间和峰面积(以离子数测量)的相对标准偏差分别为0.1%和4.5%。
Stable Copper Nanoparticle Photocatalysts for Selective Epoxidation of Alkenes with Visible Light
Selective epoxidation of various alkenes with molecular oxygen (O2) under mild conditions is a longstanding challenge in achieving syntheses of epoxides. Cu-based catalysts have been found to be catalytically active for selective epoxidations. However, the application of copper nanoparticles (CuNPs) for photocatalyzed epoxidations is encumbered by the instability of CuNPs in air. Herein we report that
A bottom up approach towards artificial oxygenases by combining iron coordination complexes and peptides
作者:Olaf Cussó、Michael W. Giuliano、Xavi Ribas、Scott J. Miller、Miquel Costas
DOI:10.1039/c7sc00099e
日期:——
Supramolecular systems resulting from the combination of peptides and a chiral ironcoordinationcomplex catalyze asymmetric epoxidation with aqueous hydrogen peroxide, providing good to excellent yields and high enantioselectivities in short reaction times. The peptide is shown to play a dual role; the terminal carboxylic acid assists the iron center in the efficient H2O2 activation step, while its β-turn structure
由肽和手性铁配位络合物的组合产生的超分子体系用过氧化氢水溶液催化不对称环氧化,在短反应时间内提供良好至优异的产率和高对映选择性。该肽显示出双重作用。末端羧酸在有效的H 2 O 2活化步骤中协助铁中心,而其β-转角结构对于在氧气输送步骤中诱导高对映选择性至关重要。这些超分子催化剂在1,1'-烷基邻位环氧化中获得高水平的立体选择(84-92%ee)迄今所描述的任何其他环氧化方法均无法获得β-取代的苯乙烯,这是用于不对称催化的极富挑战性的一类底物。目前的工作,将连接到基于N和O的配体的铁中心与形成第二个配位域的肽支架相结合,可以看作是设计人工加氧酶的一种自下而上的方法。