Nikolai S Bushkov, Andrey V Rumyantsev, Anton A Zhizhin, Tatyana V Strelkova, Roman A Novikov, Evgenii I Gutsul, Rina U Takazova, Dinara Kh Kitaeva, Nikolai A Ustynyuk, Pavel A Zhizhko, Dmitry N Zarubin
Continuing our investigation of catalytic oxo/imido heterometathesis as novel water-free method for C=N bond construction, we report here the application of classical transition metal oxides dispersed on silica (MOx/SiO2, M = V, Mo, W) as cheap, robust and readily available alternative to the catalysts prepared via Surface Organometallic Chemistry (SOMC). The oxide materials demonstrated activity in heterometathetical imidation of ketones, WO3/SiO2 being the most efficient. We also describe a new well-defined supported W imido complex (≡SiO)W(=NMes)2(Me2Pyr) (Mes = 2,4,6-Me3C6H2, Me2Pyr = 2,5-dimethylpyrrolyl) and characterize it with SOMC protocols, which allowed us to identify the position of W on the oxo/imido heterometathesis activity scale (Mo < W < Ta) and showed that W in fact provides an optimal balance between activity and stability...
April 8, 2024: ChemPlusChem