19889-99-7Relevant articles and documents
Design of stable mixed-metal MIL-101(Cr/Fe) materials with enhanced catalytic activity for the Prins reaction
álvaro, Mercedes,García, Hermenegildo,Giménez-Marqués, Mónica,Gkaniatsou, Effrosyni,Greneche, Jean-Marc,Navalón, Sergio,Santiago-Portillo, Andrea,Serre, Christian,Sicard, Clémence,Steunou, Nathalie,Vallés-García, Cristina
supporting information, p. 17002 - 17011 (2020/09/16)
This work highlights the benefit of designing mixed-metal (Cr/Fe) MOFs for enhanced chemical stability and catalytic activity. A robust and stable mixed-metal MIL-101(Cr/Fe) was prepared through a HF-free direct hydrothermal route with Fe3+ content up to 21 wt%. The incorporation of Fe3+ cations in the crystal structure was confirmed by 57Fe M?ssbauer spectrometry. The catalytic performance of the mixed metal MIL-101(Cr/Fe) was evaluated in the Prins reaction. MIL-101(Cr/Fe) exhibited a higher catalytic activity compared to MIL-101(Cr), improved chemical stability compared to MIL-101(Fe) and a higher catalytic activity for bulky substrates compared to MIL-100(Fe). In situ infra-red spectroscopy study suggests that the incorporation of Fe3+ ions in MIL-101 structure leads to an increase in Lewis acid sites. It was thus concluded that the predominant role of Cr3+ ions was to maintain the crystal structure, while Fe3+ ions enhanced the catalytic activity.
Bimetallic Radical Redox-Relay Catalysis for the Isomerization of Epoxides to Allylic Alcohols
Ye, Ke-Yin,Mccallum, Terry,Lin, Song
supporting information, (2019/06/24)
Organic radicals are generally short-lived intermediates with exceptionally high reactivity. Strategically, achieving synthetically useful transformations mediated by organic radicals requires both efficient initiation and selective termination events. Here, we report a new catalytic strategy, namely, bimetallic radical redox-relay, in the regio- and stereoselective rearrangement of epoxides to allylic alcohols. This approach exploits the rich redox chemistry of Ti and Co complexes and merges reductive epoxide ring opening (initiation) with hydrogen atom transfer (termination). Critically, upon effecting key bond-forming and -breaking events, Ti and Co catalysts undergo proton transfer/electron transfer with one another to achieve turnover, thus constituting a truly synergistic dual catalytic system.
Synthesis of bimetallic Zr(Ti)-naphthalendicarboxylate MOFs and their properties as Lewis acid catalysis
Rasero-Almansa, Antonia M.,Iglesias, Marta,Sánchez, Félix
, p. 106790 - 106797 (2016/11/23)
Bimetallic Zr(Ti)-NDC based metal-organic frameworks (MOFs) have been prepared by incorporation of titanium(iv) into zirconium(iv)-NDC-MOFs (UiO family). The resulting materials maintain thermal (up to 500 °C), chemical and structural stability with respect to parent Zr-MOFs as can be deduced from XRD, N2 adsorption, FTIR and thermal analysis. The materials have been studied in Lewis acid catalyzed reactions, such as, domino Meerwein-Ponndorf-Verley (MPV) reduction-etherification of p-methoxybenzaldehyde with butanol, isomerization of α-pinene oxide and cyclization of citronellal.