SOMC-Designed Silica Supported Tungsten Oxo Imidazolin-2-iminato Methyl Precatalyst for Olefin Metathesis Reactions

Ziyauddin S Qureshi; Ali Hamieh; Samir Barman; Niladri Maity; Manoja K Samantaray; Samy Ould-Chikh; Edy Abou-Hamad; Laura Falivene; Valerio D'Elia; Alexander Rothenberger; Isabelle Llorens; Jean-Louis Hazemann; Jean-Marie Basset

doi:10.1021/acs.inorgchem.6b02424

SOMC-Designed Silica Supported Tungsten Oxo Imidazolin-2-iminato Methyl Precatalyst for Olefin Metathesis Reactions

Inorg Chem. 2017 Jan 17;56(2):861-871. doi: 10.1021/acs.inorgchem.6b02424. Epub 2017 Jan 5.

Affiliations

¹ KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST) , 23955-6900 Thuwal, Saudi Arabia.
² Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC) , 21210, Wang Chan, Rayong, Thailand.
³ Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST) , 23955-6900 Thuwal, Saudi Arabia.
⁴ Institut de Recherches sur la Catalyse et l'Environnement de Lyon IRCELYON, UMR 5256, CNRS-Université Lyon 1 , 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex, France.
⁵ Institut Neel, CNRS , 25, avenue des Martyrs, F-38042 Grenoble Cedex 9, France.

PMID: 28055202
DOI: 10.1021/acs.inorgchem.6b02424

Abstract

Synthesis, structure, and olefin metathesis activity of a surface complex [(≡Si-O-)W(═O)(CH₃)₂-Im^DippN] (4) (Im^Dipp = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-iminato) supported on silica by a surface organometallic chemistry (SOMC) approach are reported. The reaction of N-silylated 2-iminoimidazoline with tungsten(VI) oxytetrachloride generated the tungsten oxo imidazolin-2-iminato chloride complex [Im^DippNW(═O)Cl₃] (2). This was grafted on partially dehydroxylated silica pretreated at 700 °C (SiO_2-700) to afford a well-defined monopodal surface complex [(≡Si-O-)W(═O)Cl₂-Im^DippN] (3). 3 underwent alkylation by ZnMe₂ to produce [(≡Si-O-)W(═O)(CH₃)₂-Im^DippN] (4). The alkylated surface complex was thoroughly characterized by solid-state NMR, elemental microanalysis, Raman, FT-IR spectroscopies, and XAS analysis. 4 proved to be an active precatalyst for self-metathesis of terminal olefins such as propylene and 1-hexene.