An Efficient and Practical Procedure for Synthesis of 1,1‐Diacetates from Aldehydes Catalyzed by Zirconium Sulfate Tetrahydrate–Silica Gel
作者:Tongshou Jin、Guoliang Feng、Mina Yang、Tongshuang Li
DOI:10.1081/scc-120030752
日期:2004.12.31
Abstract A facile and efficient procedure for synthesis of 1,1‐diacetatesfrom aldehydes with acetic anhydride was described using zirconium sulfate tetrahydrate–silica gel as catalyst in excellent yields under mild reaction conditions.
Amorphous carbon-silica composites bearing sulfonic acid as solid acid catalysts for the chemoselective protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations
作者:Princy Gupta、Satya Paul
DOI:10.1039/c0gc00900h
日期:——
Amorphous carbon-silica composites bearing sulfonic acid derived from inexpensive natural organic compounds (glucose, maltose, cellulose, chitosan and starch) were prepared by partial carbonization followed by sulfonation and their catalytic activity was evaluated for the protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations under solvent-free conditions. Different biomaterials have been chosen, with a view to select the most active solid acid catalyst. Carbon-silica composites were characterized by FTIR, XRD and elemental analysis. Sulfonated carbon-silica composite derived from starch was found to be the most active and could be recycled for several runs without loss of significant activity. It was also characterized by TGA, SEM and TEM.
Schiff base complex of metal ions supported on superparamagnetic Fe3O4@SiO2 nanoparticles: An efficient, selective and recyclable catalyst for synthesis of 1,1-diacetates from aldehydes under solvent-free conditions
the identification of these structures. The catalytic ability of Fe3O4@SiO2/Schiff base complex of metal ions was found to be an efficient nanocatalyst for the conversion of aldehydes to their corresponding 1,1-diacetates compounds under mild and solvent-freeconditions at room temperature. This method gives notable advantages such as excellent chemoselectivity, mild reaction condition, short reaction
我们报告了一种新的多步法制备具有高饱和磁化强度的功能化超顺磁性Fe 3 O 4 @SiO 2。在第一步中,以纳米Fe 3 O 4为核,TEOS为二氧化硅源,PVA为表面活性剂,合成了Fe 3 O 4 @SiO 2纳米球核-壳。然后,由席夫碱与金属乙酸盐[Co(OAc)2,Mn(OAc)2,Ni(OAc)2,Cu(OAc)2,Hg(OAc)2,Cr (OAc)3和Cd(OAc)2在Fe 3 O 4 @SiO 2表面上。通过透射电子显微镜(TEM)和振动样品磁强计(VSM)仪器鉴定功能化磁性二氧化硅的结构和磁性。此外,功能化的Fe 3 O 4 @SiO 2具有超顺磁特性,饱和磁化强度约为34 emu / g。NMR,FT-IR,元素分析和XRD也用于鉴定这些结构。Fe 3 O 4 @SiO 2的催化能力发现金属离子的/席夫碱络合物是在室温下在温和且无溶剂的条件下将醛转化为其相应的1,1-二乙酸
A New, Mild, and Rapid Transformation of Acylals to Bisulfites in One-Pot Synthesis by Bismuth (III) Nitrate Pentahydrate
作者:Mohammad Mehdi Khodaei、Davood Kordestani
DOI:10.1080/104265090921119
日期:2005.11.1
Abstract Direct conversion of acylals to the corresponding bisulfites can be easily performed in the presence of bismuth (III) nitrate pentahydrate in ethanol at room temperature in good yields.