Silica‐Grafted Tris(neopentyl)aluminum: A Monomeric Aluminum Solid Co‐catalyst for Efficient Nickel‐Catalyzed Ethene Dimerization. Issue 37 (29th June 2020)

• Record Type: Journal Article
• Authors: Moroz, Ilia B.; Florian, Pierre; Viger‐Gravel, Jasmine; Gordon, Christopher P.; Lesage, Anne; Copéret, Christophe
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 37(2020)
• Page Start: 16167
• Page End: 16172
• Publication Date: 2020-06-29
• Subjects: alkylaluminum -- 27Al solid-state NMR spectroscopy -- co-catalysts -- DFT computations -- ethene oligomerization -- nickel; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202006285
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A silica‐supported monomeric alkylaluminum co‐catalyst was prepared via surface organometallic chemistry by contacting tris(neopentyl)aluminum and partially dehydroxylated silica. This system, fully characterized by solid‐state 27 Al NMR spectroscopy augmented by computational studies, efficiently activates ( n Bu3 P)2 NiCl2 towards dimerization of ethene, demonstrating comparable activity to previously reported dimeric diethylaluminum chloride supported on silica. Three types of aluminum surface species have been identified: monografted tetracoordinated Al species as well as two types of bisgrafted Al species—tetra‐ and pentacoordinated. Of them, only the monografted Al species is proposed to be able to activate the ( n Bu3 P)2 NiCl2 complex and generate the active cationic species. Abstract : Isolation for activity : A solid co‐catalyst with monomeric Al sites for Ni‐catalyzed ethene dimerization was prepared by grafting Al(CH2 t Bu)3 on partially dehydroxylated silica and characterized by 27 Al solid‐state NMR spectroscopy augmented by DFT computations. The efficient co‐catalytic properties of the material were attributed to the presence of monografted alkylaluminum species, representing 19 % of all Al species.