A metal-organic framework (MOF) MIL-101 bearing sulfonic acid groups (SO3 H-MIL-101), was prepared through one-pot hydrothermal synthesis strategy. This MOF was systemically characterized via XRD, N-2 adsorption, acid-base titration, XPS, FT-IR techniques, and elemental analysis, and then used as a heterogeneous catalyst for liquid-phase acetalizations of various aldehydes with diols. The obtained SO3H-MIL-101 shows high catalytic activity in the acetalizations due to the high utilization efficiency of its functionalized acid sites. Additionally, this catalyst can be easily recovered and reused five times in succession without significant loss of catalytic activity. (C) 2013 Elsevier B.V. All rights reserved.
US4180646A
申请人:——
公开号:US4180646A
公开(公告)日:1979-12-25
Phosphotungstic Acid Supported on Magnetic Mesoporous Tantalum Pentoxide Microspheres: Efficient Heterogeneous Catalysts for Acetalization of Benzaldehyde with Ethylene Glycol
magnetization. The catalytic activity was evaluated by the acetalization of different aldehydes with diols, and the results show that Fe 3 O 4 @C@mTa 2 O 5 -NH 2 -PW 12 (14.47%) catalyst exhibits the highest catalytic activity for acetalization of aldehydes with glycols with 94.5% conversion of benzaldehyde and 99% selectivity to benzaldehyde glycol acetal at 80 °C. The catalytic activity of the catalyst
摘要 本研究通过以下方法制备了具有不同 H 3 PW 12 O 40 负载量 [Fe 3 O 4 @C@mTa 2 O 5 -NH 2 -PW 12 (w%)] 的磁性可回收核壳催化剂。磷钨酸负载在氨基官能化磁性核壳介孔五氧化二钽微球上的应用 制备的样品通过FT-IR、N 2 -吸附-解吸等温线、TEM、SEM、吡啶-IR分析、XRD和磁性表征。Fe 3 O 4 @C@mTa 2 O 5 -NH 2 -PW 12 样品同时具有布朗斯台德和路易斯酸度、大 BET 表面积和高磁化强度。通过不同醛与二醇的缩醛化反应来评价催化活性,结果表明Fe 3 O 4 @C@mTa 2 O 5 -NH 2 -PW 12 (14.47%)催化剂对醛的缩醛化表现出最高的催化活性与乙二醇与 94。80 °C 时苯甲醛的转化率为 5%,苯甲醛乙二醇缩醛的选择性为 99%。缩醛化催化剂的催化活性与其总酸度和 Brönsted-Lewis
Conformational Flexibility as a Tool for Enabling Site-Selective Functionalization of Unactivated <i>sp</i><sup><i>3</i></sup> C–O Bonds in Cyclic Acetals
作者:Ciro Romano、Laura Talavera、Enrique Gómez-Bengoa、Ruben Martin
DOI:10.1021/jacs.2c04513
日期:2022.7.6
A dual catalytic manifold that enables site-selective functionalization of unactivated sp3 C–O bonds in cyclic acetals with aryl and alkyl halides is reported. The reaction is triggered by an appropriate σ*–p orbital overlap prior to sp3 C–O cleavage, thus highlighting the importance of conformational flexibility in both reactivity and site selectivity. The protocol is characterized by its excellent