6814-19-3Relevant academic research and scientific papers
Selective hydrogenation of phenol to cyclohexanone by SiO2-supported rhodium nanoparticles under mild conditions
Zhang, Hongwei,Han, Aijuan,Okumura, Kazu,Zhong, Lixiang,Li, Shuzhou,Jaenicke, Stephan,Chuah, Gaik-Khuan
, p. 354 - 365 (2018/06/26)
A silica-supported rhodium catalyst for the selective hydrogenation of phenol to cyclohexanone under mild conditions has been developed. As the Rh concentration on the catalyst increased from 0.5 to 15 wt%, the conversion (at phenol/Rh mole ratio 100/1) dropped whereas the initial selectivity to cyclohexanone increased. The direct hydrogenation to cyclohexanol occurred in parallel with partial hydrogenation to cyclohexanone. The negative correlation between selectivity and Rh dispersion suggests that direct hydrogenation occurs at low coordination sites whereas dissociation of phenol to phenoxy followed by hydrogenation to cyclohexanone takes place at higher coordinated terrace sites. DFT calculations revealed that the activation barrier for O–H bond cleavage is lower for phenol adsorbed on a Rh(1 1 1) flat surface than on small particles. By blocking the low coordination edge and step sites through grafting with (3-mercaptopropyl)trimethoxysilane, the cyclohexanone selectivity was improved from 82 to 93% at 100% conversion. The catalyst is active at room temperature and 1 atm H2 pressure and can be easily activated by in-situ reduction.
Method for preparing aromatic secondary amino compound
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, (2008/06/13)
Disclosed are (1) a method for preparing an aromatic secondary amino compound which comprises reacting an N-cyclohexylideneamino compound in the presence of a hydrogen moving catalyst and a hydrogen acceptor by the use of a sulfur-free polar solvent and/or a cocatalyst, and (2) a method for preparing an aromatic secondary amino compound which comprises reacting cyclohexanone or a nucleus-substituted cyclohexanone, an amine and a nitro compound corresponding to the amine in a sulfur-free polar solvent in the presence of a hydrogen moving catalyst, a cocatalyst being added or not added. In a further aspect, a method is provided for the preparation of aminodiphenylamine by reacting phenylenediamine and cyclohexanone in the presence of a hydrogen transfer catalyst in a sulfur-free polar solvent while using nitroaniline as a hydrogen acceptor.
Method for preparing aromatic secondary amino compound
-
, (2008/06/13)
Disclosed are (1) a method for preparing an aromatic secondary amino compound which comprises reacting an N-cyclohexylideneamino compound in the presence of a hydrogen moving catalyst and a hydrogen acceptor by the use of a sulfur-free polar solvent and/or a cocatalyst, and (2) a method for preparing an aromatic secondary amino compound which comprises reacting cyclohexanone or a nucleus-substituted cyclohexanone, an amine and a nitro compound corresponding to the amine in a sulfur-free polar solvent in the presence of a hydrogen moving catalyst, a cocatalyst being added or not added.
Aliphatic Liquid Crystals, 2. Some Nematic Derivatives of all-trans-Perhydrophenanthrene
Sucrow, Wolfgang,Minas, Hermann,Stegemeyer, Horst,Geschwinder, Peter,Murawski, Hans-Ruediger,Krueger, Carl
, p. 3332 - 3349 (2007/10/02)
A stereoselective synthesis of the all-trans-7-alkylperhydro-2-phenanthrenols 15a-f in 11 steps and 28 liquid crystalline esters 16 of 15a-f are described, additionally some further derivatives of 7-alkylperhydro-2-phenanthrenol.An X-ray structure analysis of ester 16ec is reported.
