A new and efficient method for aldol reaction using tetramethylguanidine-functionalized magnetic nanoparticles

One of the most significant and well-known carbon-carbon bond forming synthetic reactions, functional in organic syntheses, is aldol reaction. These reactions provide high atom economies and produce β-hydroxycarbonyl structural unit [1,2]. Guanidine derivatives as strong organic super-bases have attracted much attention in synthetic organic chemistry. 1,1,3,3-tetramethylguanidine (TMG) as a typical and basic guanidine compound has been utilized in many different kinds of bases-catalyzed reactions [3,4]. In the present work tetramethylguanidine supported onto magnetic nanoparticles was prepared and characterized by different techniques including: TEM, SEM, XRD, TGA and FT-IR analyses. The prepared catalyst used as an efficient catalyst for the aldol reaction of acetone with various aldehydes to achieve β-hydroxy carbonyl compounds in excellent yields (Scheme 1). This procedure has several advantages, such as mild reaction conditions, short reaction time, excellent yields and easy purification of the products. Additionally, supporting this organosuperbase catalyst on magnetic nanoparticles offers a simple method for easy recovery and reuse of the catalyst using an external magnetic field.