No abstract

Highly ordered Metal-tetrakis(carboxyphenyl)porphyrin (Metal = Fe, Cu, Sn) bridged periodic mesoporous organosilicas (M-TCPP-PMO) with high surface area were synthesized from corresponding M-tetrakis(carboxyphenyl)porphyrin-silsesquioxanes as tetra-silanes by the solÀgel method. The BaeyerÀVilliger oxidation of ketones to the corresponding esters using molecular oxygen as an oxidant over M-TCPP-PMOs was investigated. Fe-TCPP-PMO was found to exhibit higher catalytic activity than Cu-TCPP-PMO and Sn-TCPP-PMO. The high catalytic activity is attributed to the high-valent Fe-porphyrin on the wall of mesoporous silica along with cyclohexanone, which results in successful completion of the oxygen transfer step and generation of ε-caprolactone. The obtained results demonstrate that Fe-TCPP-PMO is a promising and efficient catalyst for the BaeyerÀVilliger oxidation of ketones to esters using O 2 as the oxidant.

No abstract

Plugged mesoporous SBA-15 having a 2-D hexagonal pore structure could be directly synthesized under acidic conditions using P123 as a supramolecular template, sodium metasilicate and alcoholamines. The use of alcoholamines seemed to play roles as capturing agents for silica sources that could form internal porous plugs.

No abstract

Tirazine based microporous polymeric (TMP) network was found to be an efficient metal-free catalyst for the epoxidation of styrene. The reactions were performed in water as an environmentally benign medium using H 2 O 2 as a green oxidant at ambient temperature. The reaction afforded higher yield with 90% conversion of styrene and 98% selectivity to styrene oxide in 6 h. The triazine based microporous polymeric network can be readily recovered and reused up to 4 cycles without significant loss in catalytic activity and selectivity.

No abstract

Efficient synthesis of 1,4-disubstituted 1,2,3-triazoles using Cu(ii)-PBS-HPMO as a heterogeneous catalyst.