Environmentally Friendly ILSO₃H‐SnCl₅@Ti‐MCM‐4‐Mediated Hydroxyalkylation of Aromatic Hydrocarbons with Paraformaldehyde to Diarylmethanes

Abstract

A series of mesoporous silica supported ILs were prepared, characterized and their catalytic performances in hydroxyalkylation of aromatic hydrocarbons with paraformaldehyde were investigated. The influences of reaction parameters were studied. Research shows that ILSO3H‐SnCl5@Ti‐MCM‐41 could be used as the highest efficient catalyst in hydroxyalkylation of aromatic hydrocarbons with paraformaldehyde to gives the corresponding diarylmethanes. Good to excellent yields were achieved for this reaction under mild conditions. The heterogeneous supported catalyst is easily recoverable by filtration, and could be used for six consecutive runs without significant loss in catalytic activity.

Pd/C embedded crosslinked polystyrene fibers as an efficient catalyst for Heck reactions

“…The Pd/C@PS displays the typical adsorption peaks assigned to the phenyl (ν benzene skeleton : 1490 cm −1 , 1451 cm −1 ; β CH : 1029 cm −1 ; βCH: 753 cm −1 , 697 cm −1 ) and methylene groups (ν CH2 : 2920 cm −1 , 2851 cm −1 ). After crosslinking, the appearances of absorption peaks at 3416 cm −1 (due to ν OH ), 1124 cm −1 and 1035 cm −1 (due to ν OSO ) clearly indicate that the sulfonic groups (SO 3 H) are covalently bonded to phenyl groups after crosslinking 23,27 . According to the literatures, 28,29 the SO 3 H groups can interact with palladium species, which then can improve the stability of palladium species in the following catalysis.…”

“…There was no particle observed on the fibers, indicating the embedment of Pd/C particles inside the fibers. In order to improve the solvent resistance, the polystyrene molecules inside the composite fibers were crosslinked by paraformaldehyde with sulfuric acid as the catalyst and solvent 23,27 . After crosslinking, many fibers were broken, which might be due to the high reactivity of concentrated sulfuric acid (Figure 1b).…”

Temperature‐Assisted Generation of Arylmethyl Radicals from Bis(arylmethyl)tin Dichlorides: Efficient Reagents for − Bond‐Forming Reactions

“…Elemental analysis calcd (%) for (C 19 H 24 ) ( 3 b ): C 90.42, H 9.58 Found: C 90.64, H 9.54. This is a known compound [27] …”

“…This is a known compound. [27] Compound 3 c: 1 c (50 mg, 0.12 mmol), I 2 (32 mg, 0.12 mmol) and mesitylene (3 mL); R f = 0.53 (petroleum ether); Yield: 35 mg, 62 %, 80 % (with I 2 ), white crystalline solid, m.p. 50 °C.…”