Generation of γ-functionalized alkynyl ligands by migratory insertion of an allenylidene unit into a M–OR bond

Abstract

The hydroxyrhodium(I) complexes 2a,b, which are prepared from the corresponding chloro derivatives 1a,b and KOBu^t, react with acetic acid and phenol at room temperature to give the new acetato and phenolato metal compounds 3a,b and 4a,b almost quantitatively; subsequent treatment of 3a,b and 4a,b with CO leads to migratory insertion of the allenylidene unit into the Rh–OR bond to yield γ-functionalized alkynyl ligands.