15561-29-2Relevant academic research and scientific papers
Highly selective aromatic alkylation of phenol and anisole by using recyclable bronsted acidic ionic liquid systems
Titze-Frech, Karin,Ignatiev, Nikolai,Uerdingen, Marc,Schulz, Peter Steffen,Wasserscheid, Peter
supporting information, p. 6961 - 6966 (2013/11/06)
A highly efficient ionic liquid catalyst system for selective alkylation of phenol and anisole with alkenes is described. By using Bronsted acidic triflate ionic liquids containing the SO3H group attached to the cation, it was possible to recycle the catalyst and reuse it after a simple workup procedure. Moreover, selectivity towards the monoalkylated products was improved to 93 % by using a biphasic system. A sulfonic acid functionalized ionic liquid is used as catalyst in the hexylation of phenol and anisol, enabling very high product selectivities, simple product isolation and effective catalyst recycling. The observed selectivity boost is mainly due to differential solubility effects of the liquid-liquid biphasic reaction system established by the ionic liquid catalyst. Copyright
Versatile friedel-crafts-type alkylation of benzene derivatives using a molybdenum complex/ortho-chloranil catalytic system
Yamamoto, Yoshihiko,Itonaga, Kouhei
experimental part, p. 10705 - 10715 (2009/12/01)
A variety of molybdenum complexes catalyze Friedel-Crafts-type alkylation reactions of benzene derivatives with alkenes and alcohols in the presence of an organic oxidant, o-chloranil. The utilization of [Mo(CO)6] and two equivalents of o-chloranil catalytically furnished the hydroarylation product of norbornene with p-xylene at 80°C, whereas [Cr(CO)6] and [W(CO)6] failed to catalyze the same reaction, thus indicating the importance of the molybdenum source. The best results were obtained when a molybdenum(II) complex [CpMoCl(CO)3] (Cp = cyclopentadienyl) was used as a precatalyst. The hydroarylation reactions also took place with styrenes, cyclohexenes, and 1 -hexene as olefin substrates. The electrophilic-substitution mechanism was proposed on the basis of the ortho/para selectivities and the Markovnikov selectivities observed for the hydroarylation products. Our hypothesis was further corroborated by the fact that in the presence of the [CpMoCl(CO)3]/o-chloranil catalytic system, secondary, benzylic, or allylic alcohols participated in the alkylation of benzenes with similar selectivities.
