Periodic mesoporous silica chloride

Karimi et al. reported a variety of water-tolerant ordered nanoporous silicas functionalized with sulfonic acids for the Pechmann reaction, satisfying both recyclability and reactivity [65]. More recently, some of the authors developed a new family of periodic mesoporous silica chloride (PMSCl) synthesized by direct chlorination of SBA-15 with thionyl chloride the resulting material with 2D-hexagonal symmetry showed both high loading of Si-Cl moieties and thermal stability [66]. PMSCl efficiently catalyzed the synthesis of coumarins from a variety of phenols and ethyl acetoacetate, at 403 K, even much more than other sulfonic acids supporting mesoporous silicas, yielding coumarin 17 in almost quantitative yield in only Ih of reaction time. 

B. Karimi, H. Behzadnia, Periodic mesoporous silica chloride (PMSCl) as an efficient and recyclable catalyst for the Pechmann reaction, Catal. Commun. 12 (2011) 1432-1436. 

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