1,1,3,3-Tetramethylguanidine immobilized on graphene oxide: A highly active and selective heterogeneous catalyst for Aldol reaction

Developing efficient catalysts with high yields of aldol products in the aldol reaction is of great importance and remains a challenge. By a facile route utilizing hydrogen bonding, 1,1,3,3-tetramethylguanidine was successfully loaded on graphene oxide to afford a immobilized catalyst. This immobilized Catalyst shows an excellent conversion of 97.3% with a high aldol product selectivity of 92.5% in the aldol reaction of p-nitrobenzaldehyde with acetone, which is superior to the corresponding homogeneous catalyst with a conversion of 97.1% and selectivity of only 59.5% under similar conditions. Furthermore, the immobilized catalyst can be easily recovered and reused without significant loss of the reactivity. (C) 2016 Elsevier B.V. All rights reserved.