A well-defined silica-supported aluminium alkyl through an unprecedented, consecutive two-step protonolysis–alkyl transfer mechanism

Abstract

Impregnation of [(AliBu(3))(Et(2)O)] on partially dehydroxylated SBA-15 affords a mesoporous material bearing the well-defined single site surface aluminium species [(≡SiO)(2)Al(iBu)(Et(2)O)].

Well-defined silica supported aluminum hydride: another step towards the utopian single site dream?

“…66 However, as previously describes by Espinas et al 27 Al NMR signals are notoriously difficult to observe to very broad line shape. 41 As frequently observed in SOMC, 2 Al center coordinate to the silica surface (Si–O–Si) affording Al-surfaces complexes with different Al chemical shifts. The Al Oh species are closer to the surface and so are assumed to be due to the reaction of TIBA with the strained siloxane whereas the Al Th species are issued from the reaction of single silanol with TIBA.…”

Development of silica-supported frustrated Lewis pairs: highly active transition metal-free catalysts for the Z-selective reduction of alkynes

“…Treatment of this silica with AliBu 3 in diethylether afforded bipodal surface species [(≡SiO) 2 Al(iBu)(Et 2 O)] 1, with a concomitant transfer of isobutyl ligand onto an adjacent silicon atom, to yield an adjacent [≡Si-iBu] fragment, 66 as confirmed by DRIFT (Figure 1, a), elemental analysis (0.8 wt% Al) and 1 H MAS NMR (Figure S1a), 13 C CP/MAS NMR (Figure 2a). This material was then treated with (4hydroxyphenyl)diphenylphosphine (1.3 eq.…”

Design and Application of a Hybrid Material Featuring Well‐Defined, Tuneable Grafting Sites for Supported Catalysis.

“…We have recently described the new, well‐defined, single‐site bipodal aluminum isobutyl etherate species [(≡SiO) 2 Al( i Bu)(Et 2 O)] on SBA‐15 ‐700 16. Herein, we employ its silica counterparts (on Aerosil 200 from Evonik) as the starting material to generate a new and easily accessible organic–inorganic hybrid support by treatment with hydroquinone or tetrafluorinated hydroquinone.…”