7206-17-9Relevant articles and documents
Extension of surface organometallic chemistry to metal?organic frameworks: Development of a well-defined single site [(≡Zr? O?)W(=O)(CH2TBu)3] olefin metathesis catalyst
Thiam, Zeynabou,Abou-Hamad, Edy,Dereli, Busra,Liu, Lingmei,Emwas, Abdul-Hamid,Ahmad, Rafia,Jiang, Hao,Isah, Abdulrahman Adamu,Ndiaye, Papa Birame,Taoufik, Mostafa,Han, Yu,Cavallo, Luigi,Basset, Jean-Marie,Eddaoudi, Mohamed
supporting information, p. 16690 - 16703 (2020/11/09)
We report here the first step by step anchoring of a W(≡CtBu)(CH2tBu)3 complex on a highly crystalline and mesoporous MOF, namely Zr-NU-1000, using a Surface Organometallic Chemistry (SOMC) concept and methodology. SOMC allowed us to selectively graft the complex on the Zr6 clusters and characterize the obtained single site material using state of the art experimental methods including extensive solid-state NMR techniques and HAADF-STEM imaging. Further FT?IR spectroscopy revealed the presence of a W=O moiety arising from the in situ reaction of the W≡CtBu functionality with the coordinated water coming from the 8-connected hexanuclear Zr6 clusters. All the steps leading to the final grafted molecular complex have been identified by DFT. The obtained material was tested for gas phase and liquid phase olefin metathesis and exhibited higher catalytic activity than the corresponding catalysts synthesized by different grafting methods. This contribution establishes the importance of applying SOMC to MOF chemistry to get well-defined single site catalyst on MOF inorganic secondary building units, in particular the in situ synthesis of W=O alkyl complexes from their W carbyne analogues.
A comparison of the activity of homogeneous tungsten and ruthenium catalysts for the metathesis of 1-octene
Van Schalkwyk,Vosloo,Du Plessis
, p. 781 - 788 (2007/10/03)
The W(O-2,6-C6H3X2)2Cl 4/Bu4Sn catalytic systems (X = Ph, F, Cl, Br) have a high activity for the metathesis of terminal alkenes and a high selectivity towards primary metathesis products. Tungsten(VI) alkoxide complexes are not nearly as active as the tungsten(VI) aryloxide complexes. Bronsted acids such as HOAc, BuOH and H2O deactivate both the W(O-2,6-C6H 3X2)2Cl4/Bu4Sn (X = Cl and Ph) catalytic systems. The Lewis base (BuOAc) showed no deactivation of the catalytic systems. The Grubbs catalyst, RuCl2(PCy3) 2(=CHPh), is very active for the metathesis of 1-alkenes, even at an alkene/Ru molar ratio = 100,000. Selectivities > 93% were generally obtained. The ruthenium catalyst is active at low temperatures (25°C) and high temperatures (130°C). It shows a high tolerance towards oxygen-containing additives. The polarity of the solvent plays a major role in the activity and also the selectivity of especially the W(O-2,6-C6H3X 2)2Cl4/Bu4Sn catalytic systems.
METATHESIS OF FUNCTIONAL DERIVATIVES OF OLEFINS BY THE ACTION OF THE WCl6-1,1,3,3-TETRAMETHYL-1,3-DISILACYCLOBUTANE CATALYTIC SYSTEM
Bespalova, N. B.,Bovina, M. A.
, p. 156 - 159 (2007/10/02)
A study was carried out on the metathesis of esters of unsaturated carboxylic acids and nitriles by the action of the WCl6-1,1,3,3-tetramethyl-1,3-disilacyclobutane catalytic system.The possibility of efficient homometathesis and cometathesis with α-olefins and allyltrimethylsilane was demonstrated for ethyl 4-pentenoate and allyl cyanide.
