Acid–base cooperativity of heterogeneous catalyst containing acidic framework and sterically hindered base for aldol condensation

A bifunctional heterogeneous catalyst containing two mutually incompatible acidic and basic sites, which exhibits cooperative catalytic behavior in the aldol condensation of acetone and various aldehydes, was synthesized by postgrafting of 1,5,7-triazabicyclo[4.4.0] dec-5-ene (TBD, a sterically hindered organic base) onto Al-MCM-41 molecular sieve.