Selective Activation of Alkyl– and Aryl–Oxygen Single Bonds in Solution with Transition Metal Complexes

An unprecedented metal insertion into the strong sp2sp3 arylO bond to form 2 is observed for the reaction of [{RhCl(C8H14)2}2] (C8H14 = cyclooctene) with two equivalents of the aryl ether phosphane 1. This reaction proceeds directly, even at room temperature, with no rhodium insertion into the adjacent weaker ArOCH3 bond. However, the alkylO bond is activated by the reaction of 1 with [Pd-(CF3CO2)2] to give 3. Selectivity of CO activation can therefore be directed by choice of metal complex.