Synthesis of Alkynyl Ketones by Sonogashira Cross-Coupling of Acyl Chlorides with Terminal Alkynes Mediated by Palladium Catalysts Deposited over Donor-Functionalized Silica Gel

Abstract

Palladium catalysts deposited over silica gel bearing simple amine (≡Si(CH2)3NH2) and composite functional amide pendants equipped with various donor groups in the terminal position (≡Si(CH2)3NHC(O)CH2Y, Y = SMe, NMe2 and PPh2) were prepared and evaluated in Sonogashira-type cross-coupling of acyl chlorides with terminal alkynes to give 1,3-disubstituted prop-2-yn-1-ones. Generally, the catalysts showed good catalytic activity in the reactions of aroyl chlorides with aryl alkynes under relatively mild reaction conditions even without adding a copper co-catalyst. However, their repeated use was compromised by a significant loss of activity after the first catalytic run.

Oxime Palladacycle Supported on Magnetic Meoporous Silica: An Efficient Catalyst for Copper‐Free Acyl Sonogashira Reaction

“…[22] Loganathan et al [23] reported the immobilization of palladium nanoparticles on montmorillonite K-10 for the acyl Sonogashira reaction of aryl/heteroaryl acetylenes with acid chlorides under copper-free conditions. Semler et al [24] reported the application of palladium catalysts deposited over silica gel bearing donor-substituted amide pendants in the copper-free acyl Sonogashira reaction; however, a significant catalyst deactivation was observed after the first catalytic run. Patel and Vasava [25] reported the acyl Sonogashira reaction catalyzed by copper nanoparticles embedded in modified polystyrene resin.…”

Editorial Catalysts: Special Issue on Transition Metal Catalyzed Cross-Coupling Reactions

“…In a second article, Štȇpnička and co-workers describe the preparation of palladium catalysts deposited over silica gel bearing composite amide-donor functional moieties on the surface [14]. These heterogeneous catalysts were evaluated in the Sonogashira-type cross-coupling of acyl chlorides with terminal alkynes producing synthetically useful 1,3disubstituted prop-2-yn-1-ones.…”