32094-31-8Relevant academic research and scientific papers
Highly sulfonated graphene and graphene oxide nanosheets as heterogeneous nanocatalysts in green synthesis of bisphenolic antioxidants under solvent free conditions
Naeimi, Hossein,Golestanzadeh, Mohsen
, p. 56475 - 56488 (2014)
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. In this research, three types of the catalysts including sulfonated reduced graphene oxide nanosheets (catalyst 1a), sulfonated graphene oxide nanosheets (catalyst 1b), and sulfonated propylsilane graphene oxide nanosheets (catalyst 1c) were synthesized and used in the synthesis of target molecules. The catalysts were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction spectroscopy (XRD), and back acid-base titration. The catalyst 1a showed excellent catalytic activity in the green synthesis of 6,6′-(arylmethylene)bis(2,4-dialkylphenol) antioxidants under solvent free conditions and was reused several times without any appreciable loss of its catalytic activity even after eight consecutive cycles. In addition, the high yield of the products and non-toxicity of the catalysts are other worthwhile advantages of the present methods.
Microwave-assisted synthesis of 6,6′-(aryl(alkyl)methylene)bis(2,4-dialkylphenol) antioxidants catalyzed by multi-sulfonated reduced graphene oxide nanosheets in water
Naeimi, Hossein,Golestanzadeh, Mohsen
, p. 2697 - 2710 (2015)
Sulfonated reduced graphene oxide nanosheets (RGO-SO3H) were characterized using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and acid-base titration. Multi-SO3H supported on reduced graphene oxide nanosheets was found to be an efficient catalyst for the green synthesis of 6,6′-(aryl(alkyl)methylene)bis(2,4-dialkylphenol) derivatives from 2,4-dialkylphenols and aromatic and aliphatic aldehydes in aqueous media under microwave irradiation. The synthesis of 6,6′-(aryl(alkyl)methylene)bis(2,4-dialkylphenol) derivatives were carried out in the presence of a catalytic amount of RGO-SO3H, under thermal and microwave conditions to afford the desired products in high and excellent yields respectively. In addition, the catalyst could be recovered easily and reused several times without any considerable loss of its catalytic activity.
Spirans. Part 13. The Synthesis and Orientation of Spirans related to Abel's Ketone (Naphthofuran-2(1H)-spiro-1'(2'H)-naphthalen-2'-one)
Dean, Francis M.,Herbin, G. Antonio,Matkin, David A.,Price, Anthony W.,Robinson, Malcolm L.
, p. 1986 - 1993 (2007/10/02)
The aryl substituents in the stereoisomers (2) and (3) of 1-phenylnaphthofuran-2(1H)-spiro-1'(2'H)-naphthalen-2'-one are subject to hindered rotation by an energy barrier of ca. 15 kcal mol-1.If the phenyl substituent carries an ortho substituent, however, rotation is prevented at temperatures up to 60 deg C (the highest examined): only one rotamer is obtainable (the other is too crowded) and it has the ortho-substituent cisoid with respect to the triarylmethine proton. The temperature-variable broadening of the signals from the protons of the aryl substituent serves to identify these in the 1H n.m.r. spectra.Some other resonances can be regularly identified by combinations of coupling constants, double-irradiation experiments, and shifts induced by using benzene instead of trichloromethane as sovent, but the only one of value for determining the configuration at the triarylmethine centre is that already known, i.e. the upfield shift in the resonance of the vinylic (3') proton caused by the aryl substituent when this lies immediately below it.A less precise but more general test of configuration is afforded by the mutual shielding of the aryl substituent and ring E when these are in adjacent planes. Methods of preparation are given for several related spirans, especially those containing the spiro-1'(4'H)-naphthalen-4'-one nucleus, and n.m.r. methods used to establish the configurations.
