Evidence for Suzuki-Miyaura cross-couplings catalyzed by ligated Pd-clusters: from cradle to grave.

Pd clusters offer unique selectivity and exploitable reactivity in catalysis. Understanding the behavior of Pd clusters is thus critical for catalysis, applied synthetic organic chemistry and greener outcomes for precious Pd. The Pd cluster, [Pd(μ-Cl)(μ-PPh)(PPh)][Cl] (denoted as PdCl), which exhibits distinctive reactivity, was synthesized and immobilized on a phosphine-functionalized polystyrene resin (denoted as immob-PdCl).

A Dichotomy in Cross-Coupling Site Selectivity in a Dihalogenated Heteroarene: Influence of Mononuclear Pd, Pd Clusters, and Pd Nanoparticles-the Case for Exploiting Pd Catalyst Speciation.

Site-selective dihalogenated heteroarene cross-coupling with organometallic reagents usually occurs at the halogen proximal to the heteroatom, enabled by intrinsic relative electrophilicity, particularly in strongly polarized systems. An archetypical example is the Suzuki-Miyaura cross-coupling (SMCC) of 2,4-dibromopyridine with organoboron species, which typically exhibit C2-arylation site-selectivity using mononuclear Pd (pre)catalysts. Given that Pd speciation, particularly aggregation, is known to lead to the formation of catalytically competent multinuclear Pd species, the influence of these species on cross-coupling site-selectivity remains largely unknown.