Microwave promoted Heck reactions using an oligo(ethylene glycol)-bound SCS palladacycle under thermomorphic conditions

Abstract

Palladium catalyzed Heck couplings utilizing an air-stable, water-soluble oligo(ethylene glycol)-bound SCS palladacycle catalyst and microwave irradiation lead to formation of several cinnamic acid derivatives with reaction times of less than 1 hour. Such couplings of various aryl halides with alkene acceptors occur in an air atmosphere with aqueous and organic solvents are described. Recycling of the catalyst was accomplished using a 10% aqueous DMA–heptane thermomorphic system that was advantageously homogeneous during these microwave promoted reactions and biphasic during the catalyst recovery step.