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

• DOI: 10.1021/jacs.1c05294
• Publication Date: 2021-06-21T14:55:27Z
• Authors: Neil W. J. Scott; Mark J. Ford; Neda Jeddi; Anthony Eyles; Lauriane Simon; Adrian C. Whitwood; Theo Tanner; Charlotte E. Willans; Ian J. S. Fairlamb
• Keywords: Heteroatom; Genetic algorithm

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