Support-Free Palladium–NHC Catalyst for Highly Recyclable Heterogeneous Suzuki–Miyaura Coupling in Neat Water

Among the various
new challenges of chemical processes in water,
research on stable, highly active, and recyclable catalysts is a prosperous
field. We present here a palladium–NHC catalyst that was synthesized with good yields through a
series of simple synthetic steps. This organometallic species was
used as a heterogeneous catalyst in low loadings for Suzuki–Miyaura
coupling in neat water, under mild conditions. Reaction conditions
were optimized for a simple, green, and support-free procedure, without
using any phase transfer agent. The catalyst shows excellent reactivity
in short times toward different substrates and a very good recyclability.