Advantageous Use of <sup><i>t</i></sup>Bu<sub>2</sub>P-NP(<sup><i>i</i></sup>BuNCH<sub>2</sub>CH<sub>2</sub>)<sub>3</sub>N in the Hiyama Coupling of Aryl Bromides and Chlorides

An efficient catalytic route to biaryls by employing (generally) only 0.25 mol % of Pd(OAc)<sub>2</sub> and 0.5 mol % of <b>1</b> in the Hiyama coupling reaction is reported. High yields for electron-rich, -neutral, and -deficient aryl chlorides are obtained. A variety of phenylsiloxanes undergo coupling with aryl bromides and chlorides with low Pd(OAc)<sub>2</sub>/<b>1</b> loadings.