Amino-functionalized mesoporous silica as solid base catalyst for regioselective aza-Michael reaction of aryl tetrazoles

The modified MCM-41 with aminopropyl groups was synthesized, characterized and its catalytic activity was evaluated in aza-Michael addition of various aryl tetrazoles to activated olefin esters under reflux condition. The synthesized new compounds were characterized using spectroscopic and physical methods. The catalyst was reused in five consecutive experiments without obvious loss of activity. The results showed with application of aminopropylated MCM-41 only N2 alkylation occurs on tetrazole rings. However, when triethylamine was used as the base, a mixture of N1 and N2 alkylation was observed. In addition, antimicrobial studies investigated and results indicated that the products did not show considerable antimicrobial activity.