Sulfonic or Carboxylic Acid-Amine Bifunctional Catalyst

Sulfonic or Carboxylic Acid-Amine Bifunctional Catalyst 

The above report by Jones and coworkers strongly indicates that it is necessary to keep the amount of silanols constant for the investigation of the cooperative catalysis of both organic acid and base groups. Additionally, it can be said that surface silanol groups possess potential usefulness for the promotion of amine-catalyzed reactions. The detailed role of silanol groups in the cooperative catalysis will be discussed in the next section. 

Bifunctional Catalysts Possessing Basic Organic Croups and Acid Sites Derived from Their Support Surface 

Organic Base-Catalyzed Reactions Enhanced bySiO, 

Amine-catalyzed aldol reaction enhanced by Si02 was reported by Kubota and coworkers in 2003 [8]. In the reaction of 4-nitrobenzaldehyde with acetone catalyzed by piperazine, the addition of mesoporous silica FSM-16 induced the increase in yield of the product from 5% to 91%. Several secondary amines were used as catalysts. In addition, the authors also investigated the amine-immobilized silicas 

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