Csp2-Br bond activation of Br-pyridine by neophylpalladacycle: formation of binuclear seven-membered palladacycle and bipyridine speciesElectronic supplementary information (ESI) available: Experimental details for the synthesis and characterization of all compounds. See DOI: 10.1039/c7nj02468a

In this work, the synthesis and reactivity of seven-membered palladacycles are described, and a novel bi-pyridine synthesis in a catalytic pathway is reported. Neophyl-palladacycle( i ) reacts with an excess of 2-Br-pyridine, giving the desired new binuclear seven-membered palladacycle ( 1 ) and unexpectedly, a bipyridine complex, [Pd(BiPy)Br 2 ]. ESI-HRMS experiments show that fragmentation of the Pd-Br bond in 1 can take place producing unusual two coordinated Pd( ii ) molecular ions, [Pd(NeoPyR)] + . A small library of seven-membered palladacycles and asymmetric bipyridines was prepared via C-Br activation and C-C coupling reactions.