Oxidative Addition of B–Br Bonds to Pd⁰: Synthesis and Structure of trans‐Bromo(boryl)palladium Complexes

The oxidative addition of several bromoboranes to the Pd 0 species [Pd(PCy 3 ) 2 ] yielded the novel palladium boryl complexes trans ‐[(Cy 3 P) 2 Pd(Br)(BCat)] ( 1 ) (Cat = 1,2‐dioxophenylene), trans ‐[(Cy 3 P) 2 Pd(Br)(BCat′)] ( 2 ) (Cat′ = Cat‐4‐ t Bu) and trans ‐[(Cy 3 P) 2 Pd(Br){B(X)X′}] {X = Br, X′ = NMe 2 ( 3 ), Pip ( 4 ) (Pip = NC 5 H 10 ), Mes ( 5 ) [Mes = 2,4,6‐(CH 3 ) 3 C 6 H 2 ]}. Compounds 1 – 5 were characterized by multinuclear NMR spectroscopy in solution; single crystals for X‐ray analyses were acquired from 2 and 3 , which thus allowed comparison of the structural data. The few palladium boryl complexes published so far were obtained by σ‐bond metathesis; the oxidative addition of the corresponding bromoboranes to Pd 0 has not yet been reported.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)