Ru^III(OTf)SalophenCH₂–NHSiO₂–Fe: an efficient and magnetically recoverable catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane

Abstract

Efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by ruthenium(III) complex of chloromethylated Salophen supported on nanomagnetic materials is reported. First, the iron nanomagnets were silica coated, functionalized with amine and then ruthenium CM-Salophen was successfully bonded to their surface. The catalyst, Ru III (OTf) SalophenCH 2 -NHSiO 2 -Fe, was characterized by elemental analysis, FT-IR and UV-visible spectroscopic techniques, transmission electron microscopy and inductively coupled plasma (ICP). The Ru III (OTf)SalophenCH 2 -NHSiO 2 -Fe catalyzed trimethylsilylation of primary and secondary alcohols as well as phenols, and the corresponding TMS ethers were obtained in high yields and short reaction times at room temperature. This new heterogenized trimethylsilylation catalyst is easily recovered with a magnet and showed no appreciable loss of activity even after five consecutive runs.

Catalytic synthesis of cyclic carbonates from epoxides and carbon dioxide by magnetic UiO‐66 under mild conditions

“…The crystallinity of the framework and nanoparticles was studied using XRD analysis. The XRD pattern of UiO‐66 (Figure A) is the same as the profile of UiO‐66 synthesized previously by Lillerud et al Also, the XRD pattern of Fe 3 O 4 @SiO 2 (Figure B) is the same as that of Fe 3 O 4 @SiO 2 in the literature . As can be seen in Figure (C), the crystallinity of UiO‐66 and Fe 3 O 4 @SiO 2 is well retained after the magnetization reaction, because all diffraction peaks of the MOF and MNPs can be readily indexed to the pattern of UiO‐66@Fe 3 O 4 @SiO 2 .…”

“…Figure (B) shows the FT‐IR spectrum of the synthesized MNPs which exhibits characteristic bands at 580 cm −1 (Fe─O), 950 cm −1 (Si─OH) and 1091 cm −1 (Si─O─Si), which are seen in the spectrum of UiO‐66 after the magnetization reaction (Figure C), proving the successful synthesis of UiO‐66@Fe 3 O 4 @SiO 2 .…”

“…UiO‐66 was prepared based on the procedure reported by Lillerud and co‐workers . The Fe 3 O 4 magnetic nanoparticles (MNPs) were synthesized and coated with silica as reported in the literature …”

Chemical fixation of carbon dioxide catalyzed by magnetically recoverable NH2-MIL-101(Al) as an elegant nanoreactor

“…The magnetic nanoparticles, MNPs (Fe 3 O 4 ), were synthesized and silica-coated as reported in the literature [32]. Also, amino-MIL-101(Al) was synthesized according to the procedure reported by Gascon et al [25,33].…”

Highly efficient protection of alcohols and phenols catalysed by tin porphyrin supported on MIL‐101

“…For this purpose, various catalysts such as K‐10 montmorillonite, zirconium sulfophenylphosphonate, iodine, H 3 PW 12 O 40 , sulfonic acid‐functionalized ordered nanoporous Na + –montmorillonite, sulfonic acid‐functionalized nanoporous silica, ZrO(OTf) 2 , Bi(OTf) 3 , [Sn IV (TPP)(BF 4 ) 2 ], nanocrystalline TiO 2 –HClO 4 , [Ti IV (salophen)(OTf) 2 ], InBr 3 , 1,3‐disulfonic acid imidazolium hydrogen sulfate, Ru III (OTf)salophenCH 2 –NHSiO 2 –Fe, alumina‐supported heteropolyoxometalates, ZrCl 4 and H 14 [NaP 5 W 29 MoO 110 ] have been introduced for the silylation of alcohols and phenols with 1,1,1,3,3,3‐hexamethyldisilazane (HMDS) as a stable, cheap and commercially available reagent. Also, various catalysts like polystyrene‐supported GaCl 3 , N , N ′‐dibromo‐ N , N ′‐1,2‐ethanediylbis(benzene sulfonamide), La(NO 3 ) 3 ⋅6H 2 O, ferric perchlorate, vanadyl(IV) acetate, activated carbon‐supported sulfuric acid, {[K.18‐crown‐6]Br 3 } n , tungstosilicate salts, silica–alumina‐supported heteropoly acids, sulfonic acid‐functionalized carbon catalyst from glycerol pitch, aniline–terephthalaldehyde resin p ‐toluenesulfonic acid salt, Al(OTf) 3 , p ‐toluenesulfonic acid, Ru(CH 3 ) 3 (triphos)](OTf) 2 and K 5 CoW 12 O 40 ⋅3H 2 O have been developed for the tetrahydropyranylation of alcohols and phenols.…”