INFLUENCE OF PRECURSOR NATURE AND TYPE OF POLYMERIC SUPPORT ON CATALYTIC ACTIVITY OF PALLADIUM-CONTAINING SYSTEMS IN SUZUKI CROSS-COUPLING.

Suzuki cross-coupling reaction is one of the most widely used and environmentally friendly methods of carbon-carbon bond formation for the synthesis of various chemicals including APIs, crop protection agents, and polymers. In this work, the Suzuki cross-coupling of 4-bromoanisole and phenylboronic acid was carried out as at ambient pressure (nitrogen atmosphere was used) while using EtOH/water mixture as a solvent at mild reaction conditions (60°C, NaOH) and at the absence of phase transfer agents. It was shown that proper combination of Pd precursor nature and the HPS type is extremely important and allows influencing sizes of Pd nanoparticles (NPs). Independently of the precursor nature and HPS type, Pd(II) was assumed to be the direct source of catalytically active forms of Pd. For the samples, which were preliminarily reduced in hydrogen flow, the use of the HPS as a support allowed formation of Pd NPs, which were the sources of active homogeneous forms. [ABSTRACT FROM AUTHOR]