71401-15-5Relevant articles and documents
Nanoscale organization of thiol and arylsulfonic acid on silica leads to a highly active and selective bifunctional, heterogeneous catalyst
Margelefsky, Eric L.,Bendjeriou, Anissa,Zeidan, Ryan K.,Dufaud, Veronique,Davis, Mark E.
experimental part, p. 13442 - 13449 (2009/02/06)
Ordered mesoporous silicas functionalized with alkylsulfonic acid and thiol group pairs have been shown to catalyze the synthesis of bisphenols from the condensation of phenol and various ketones, with activity and selectivity highly dependent on the distance between the acid and thiol. Here, a new route to thiol/sulfonic acid paired catalysts is reported. A bis-silane precursor molecule containing both a disulfide and a sulfonate ester bond is grafted onto the surface of ordered mesoporous silica, SBA-15, followed by simultaneous disulfide reduction and sulfonate ester hydrolysis. The resulting catalyst, containing organized pairs of arylsulfonic acid and thiol groups, is significantly more active than the alkylsulfonic acid/thiol paired catalyst in the synthesis of bisphenol A and Z, and this increase in activity does not lead to a loss of regioselectivity. The paired catalyst has activity similar to that of a randomly bifunctionalized arylsulfonic acid/thiol catalyst in the bisphenol A reaction but exhibits greater activity and selectivity than the randomly bifunctionalized catalyst in the bisphenol Z reaction.
Organized surface functional groups: Cooperative catalysis via thiol/sulfonic acid pairing
Margelefsky, Eric L.,Zeidan, Ryan K.,Dufaud, Veronique,Davis, Mark E.
, p. 13691 - 13697 (2008/03/27)
The synthesis and characterization of heterogeneous catalysts containing surfaces functionalized with discrete pairs of sulfonic acid and thiol groups are reported. A catalyst having acid and thiol groups separated by three carbon atoms is ca. 3 times more active than a material containing randomly distributed acid and thiol groups in the condensation of acetone and phenol to bisphenol A and 14 times more active in the condensation of cyclohexanone and phenol to bisphenol Z. Increasing the acid/thiol distance in the paired materials decreases both the activity and selectivity. This work clearly reveals the importance of nanoscale organization of two disparate functional groups on the surface of heterogeneous catalysts.
REACTION OF PHENOL WITH CYCLOHEXANONE IN THE PRESENCE OF ALUMINUM PHENOLATE
Kozlikovskii, Ya. B.,Chernyaev, B. V.
, p. 1970 - 1973 (2007/10/02)
The reaction of phenol with cyclohexanone in the presence of aluminum phenolate leads to a mixture of products of ether and phenolic character and also a mixture of the dimer and trimer of the initial ketone.As a rule 1-(2-hydroxyphenyl)cyclohexene predominates in the mixture.
