Highly sulfonated graphene and graphene oxide nanosheets as heterogeneous nanocatalysts in green synthesis of bisphenolic antioxidants under solvent free conditions

Abstract

Sulfonated functionalized graphene and graphene oxide nanosheets were prepared via chemical approaches and their catalytic activities were investigated in the green synthesis of 6,6′-(arylmethylene)bis(2,4-dialkylphenol) antioxidants.

Metal-free GO-SiPr-SO3H Nanosheets Catalyzed Ultrasound Promoted One-pot Synthesis of Star-Shape Phenolic Compounds in Water and Study of Their In-vitro Antimicrobial Activities

“…Moreover, in an effort to seek improved yields, the catalytic amount of GO‐SiPr‐SO 3 H was screened (Figure ). As shown in this Figure, the 0.85 mol% (20 mg) of the catalyst showed the best result for compound 3 a (96 %, 3.5 min, TOF: 969 (h −1 ), (US irradiation); vs 68 %, 70 min, TOF: 6.9 (h −1 ) (heating method). The TOF of the GO‐SiPr‐SO 3 H catalyst under ultrasound irradiation was superior increased relative to the heating method.…”

“…The mechanism of the reaction was shown in Scheme and previously discussed . As shown in Scheme , two carbon‐carbon bonds were formed via C−H activation under metal‐free conditions and the aldehyde ring was connected to the phenol ring through carbon of carbonyl groups.…”

“…Then, the influence of power of ultrasound in the synthesis of star‐shape phenolic compounds was checked. In previous work the GO‐SiPr‐SO 3 H catalyst was used in heating conditions and the yield and time of the reaction for preparation of compound 3 a were 68 % and 70 min (TOF: 6.9). The turnover frequency for the GO‐SiPr‐SO 3 H catalyst was very low.…”

Metal‐Free and Ultrasound‐Assisted C–C and O‐Si (O‐Protected) Bond Formation in Cyanosilylation of Aldehydes with TMSCN Catalyzed by Functionalized Graphene Oxide Derivatives

“…Also, the full details of preparation and characterization of the prepared catalysts are provided in supporting information of this paper. Previously, we have reported the synthesis of phenolic antioxidants using GO‐SO 3 H and RGO‐SO 3 H ,,–. In this study, all of the catalysts were tested in the cyanosilylation of aromatic aldehyde using TMSCN and we found that the cyanosilylation of aldehydes could be rapidly accomplished.…”

“…The sulfonated reduced graphene oxide (RGO‐SO 3 H), sulfonated graphene oxide (GO‐SO 3 H) and graphene oxide (GO) were prepared based on previous work . The schematic representation of prepared catalysts was shown in Figure .…”