Selective and efficient bifunctional and trifunctional nanoporous catalysts

Abstract

Selective and efficient multifunctional nanoporous catalysts containing spatially distributed organoamine and silanol groups, and methods of preparation thereof. The catalysts have been observed to be very highly efficient in catalysis of the Henry reaction.

1 . A multifunctional catalyst comprising a mesoporous substrate having spatially distributed cooperative acid groups and base groups grafted to the substrate. 
   
   
       2 . The catalyst of  claim 1 , wherein the acid groups are silanol groups. 
   
   
       3 . The catalyst of  claim 1 , wherein the base groups are organoamine groups. 
   
   
       4 . The catalyst of  claim 3 , wherein the organoamine groups are organomonoamine groups. 
   
   
       5 . The catalyst of  claim 3 , wherein the organoamine groups are organodiamine groups. 
   
   
       6 . The catalyst of  claim 3 , wherein the organoamine groups are 3-aminopropyl groups. 
   
   
       7 . The catalyst of  claim 3 , wherein the acid groups are silanol groups. 
   
   
       8 . The catalyst of  claim 3 , wherein the organoamine groups are spatially distributed at a density of between about 6 percent to about 15 percent of available sites. 
   
   
       9 . The catalyst of  claim 8 , wherein the ratio of silanol groups to organoamine groups is between about 2:1 to about 6:1. 
   
   
       10 . The catalyst of  claim 9 , wherein the ratio of silanol groups to organoamine groups is about 5:1. 
   
   
       11 . The catalyst of  claim 1 , wherein the base groups are selected from 3-aminopropyl, 2-aminoethyl(3-aminopropyl), and 3-cyanopropyl, and combinations thereof. 
   
   
       12 . The catalyst of  claim 1 , wherein the catalyst is bifunctional and is comprised of silanol groups and organoamine groups. 
   
   
       13 . The catalyst of  claim 1 , wherein the catalyst is trifunctional and selective and is comprised of silanol groups, base groups of first organic groups and secondary organic groups. 
   
   
       14 . The catalyst of  claim 13 , wherein the base groups of first organic groups are organoamines. 
   
   
       15 . The catalyst of  claim 13 , wherein the secondary organic groups are hydrophilic groups. 
   
   
       16 . The catalyst of  claim 13 , wherein the secondary organic groups are hydrophobic groups. 
   
   
       17 . The catalyst of  claim 13 , wherein the secondary organic groups are selected from ureidopropyl, 3-mercaptopropyl, and methyl groups. 
   
   
       18 . The catalyst of  claim 13 , wherein the molar ratio of the secondary organic groups and the base groups of first organic groups is between about 1:1 to about 9:1. 
   
   
       19 . The catalyst of  claim 1 , wherein the substrate is mesoporous silica. 
   
   
       20 . The catalyst of  claim 19  wherein the mesoporous silica is selected from the group consisting of MCM-41 and SBA-15. 
   
   
       21 . A selective trifunctional mesoporous catalyst comprising a substrate having spatially distributed acid groups, base groups of a first organosilane grafted to the substrate, and secondary organic groups of a second organosilane grafted to the substrate. 
   
   
       22 . A method of making a multifunctional catalyst comprising the step of postgrafting aminoorganosilanes in a spatially distributed manner onto a mesoporous substrate. 
   
   
       23 . A method of performing a nitroaldol reaction comprising the step of reacting an aldehyde and nitromethane in the presence of a multifunctional mesoporous catalyst comprising a substrate having spatially distributed cooperative acid groups and base groups grafted to the substrate.