固定在磁性纳米粒子上的手性氧-钒(+)-伪麻黄碱络合物:一种高效且可回收的新型纳米催化剂,用于使用H 2 O 2将硫化物化学选择性氧化为亚砜。
摘要:
利用最常见的技术设计和表征了以磁性纳米粒子Fe 3 O 4 [VO(pseudoephedrine)@MNPs]为载体的新型手性氧-钒(+)-伪麻黄碱配合物。VO(伪麻黄碱)@MNPs在室温下无溶剂条件下,以过氧化氢为绿色氧化剂,以高收率催化过量的20-27%对映异构体将硫化物化学选择性氧化为亚砜。催化剂循环使用多达20次,而活性和对映选择性几乎没有损失。
Chiral oxo-vanadium (+)-pseudoephedrine complex immobilized on magnetic nanoparticles: A highly efficient and recyclable novel nanocatalyst for the chemoselective oxidation of sulfides to sulfoxides using H2O2
作者:Amin Rostami、Bahareh Atashkar
DOI:10.1016/j.molcata.2014.12.010
日期:2015.3
designed and characterized using the most common techniques. VO(pseudoephedrine)@MNPs catalyzed the chemoselective oxidation of sulfides to sulfoxides using hydrogen peroxide as a green oxidant in high yields with 20–27% enantiomeric excesses under solvent-free conditions at room temperature. The catalyst was recycled up to 20 times with little loss of activity and enantioselectivity.
利用最常见的技术设计和表征了以磁性纳米粒子Fe 3 O 4 [VO(pseudoephedrine)@MNPs]为载体的新型手性氧-钒(+)-伪麻黄碱配合物。VO(伪麻黄碱)@MNPs在室温下无溶剂条件下,以过氧化氢为绿色氧化剂,以高收率催化过量的20-27%对映异构体将硫化物化学选择性氧化为亚砜。催化剂循环使用多达20次,而活性和对映选择性几乎没有损失。
DABCO tribromide immobilized on magnetic nanoparticle as a recyclable catalyst for the chemoselective oxidation of sulfide using H2O2 under metal- and solvent-free conditions
The catalytic activity of MNPs-DABCO tribromide was investigated in the chemoselective oxidation of sulfides to sulfoxides using 30% H2O2 as an oxidant at room temperature under solvent-free conditions. The heterogeneous catalyst could be recovered easily and reused 15 times without significant loss of its catalytic activity.
易于制备磁性纳米颗粒负载的1,4-二氮杂双环[2.2.2]辛烷三溴化物(MNPs-DABCO三溴化物)作为溴源,并通过X射线衍射(XRD),热重分析(TGA),傅里叶变换红外光谱法进行了表征(FT-IR),能量色散X射线能谱(EDX),扫描电子显微镜(SEM)和振动样品磁强(VSM)技术。在室温,无溶剂条件下,使用30%H 2 O 2作为氧化剂,研究了MNPs-DABCO三溴化物在硫化物化学选择性氧化成亚砜中的催化活性。该多相催化剂可以容易地回收并重复使用15次,而不会显着降低其催化活性。
Methods for the synthesis of a polyoxometalate compounds include heating a metal precursor in the presence of an organic salt. The polyoxometalate compounds produced herein display high photoluminescence quantum yields and photoluminescence maximums in the blue and/or violet regions of the electromagnetic spectrum.
PROCESSES FOR THE PRODUCTION OF OPTICALLY ACTIVE COMPOUNDS HAVING SUBSTITUENTS AT THE 2-POSITION
申请人:KANEKA CORPORATION
公开号:EP1600438A1
公开(公告)日:2005-11-30
The present invention provides a process for producing an optically active compound having a thio group at the 2-position important for manufacturing medicines. An optically active compound having a hydroxyl group at the 2-position is chlorinated with inversion of the configuration at the 2-position, and the resultant optically active compound having a chlorine atom at the 2-position is reacted with a metal thiolate to introduce a thio group with inversion of the configuration at the 2-position. This process is capable of minimizing racemization and producing an optically active compound having a thio group at the 2-position at low cost in high yield. When the optically active compound having a chlorine atom at the 2-position is reacted with the metal thiolate in coexistence with water in the reaction system, the optically active compound having a thio group at the 2-position with higher optical purity can be produced in higher yield. An optically active carboxylic acid having a thio group at the 2-position is crystallized in the presence of an aliphatic hydrocarbon solvent and/or a sulfur-containing solvent to effectively remove coexistent impurities such as an optical isomer and the like, thereby producing crystals of an optically active carboxylic acid having a thio group at the 2-position with higher purity.
Methods for the synthesis of a polyoxometalate compounds include heating a metal precursor in the presence of an organic salt. The polyoxometalate compounds produced herein display high photoluminescence quantum yields and photoluminescence maximums in the blue and/or violet regions of the electromagnetic spectrum.