Abstract
Hydroxyapatite [Ca5(PO4)3(OH); HAP] supported Pd catalyst has been identified as an efficient and reusable heterogeneous catalyst for the Sonogashira coupling reaction under copper and phosphine-free conditions. The 2 wt % Pd/HAP offered excellent yields (96%) compared to 2 wt % Pd/MgO and 2 wt % Pd/Al2O3 catalysts. The formic acid adsorbed diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results revealed that moderate basic sites on 2 wt % Pd/HAP are found to be selective for the Sonogashira coupling reaction. Strong basic sites present on the Pd/MgO catalyst demonstrated homocoupling of the substrate during the Sonogashira reaction. The physicochemical characteristics of the catalysts are rationalized by temperature-programmed desorption of CO2, H2-temperature-programmed reduction, formic acid adsorbed DRIFTS, Brunnauer–Emmet–Teller surface area, X-ray photoelectron spectroscopy, transmission electron microscopy, and CO chemisorption techniques. The 2 wt % Pd/HAP catalyst was recover...
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
