Water-promoted surface basicity in FeO(OH) for the synthesis of pseudoionones (PS) and their analogues

Abstract

Use of Iron oxyhydroxide (γ-FeO(OH)) as a robust catalyst for the synthesis of important intermediates like pseudoionones and their analogues through the C-C bond formation reactions like knoevenagel and aldol condensation is explored. These motifs are the building blocks for the construction of the sesquiterpenes as well as the diterpenes such as retinoic acid, Vitamin A etc. Iron oxyhydroxide (γ-FeO(OH)) was synthesized and well characterized using XRD, FT-IR, TEM, XPS and adsorption studies to establish the catalytic activity. A thorough investigation on the nature of basic sites and the role of water as a promoter was explored based on dye adsorption, in situ methanol dissociation and CO2 adsorption studies. The catalyst also showed a wide range of substrate scope with active methylene groups involving various functional groups such as cyanides, esters and acetophenones along with its stability and reproducibility.