Reaction of [(PEt 3) 3Rh{C(N 2)SiMe 3}] with terminal alkynes—synthesis of σ-alkynyl rhodium(III) complexes

Abstract

Reaction of [(PEt 3) 3Rh{C(N 2)SiMe 3}] with two equivalents of HCCR (R  SiMe 3, Ph, or tBu) affords the Rh III complex [(PEt 3) 3RhH(CCR) 2] in high yield, showing that the trimethylsilyldiazomethyl group behaves like an alkyl group. The reaction was followed by 31P and 1H NMR spectroscopy. The first step is the oxidative addition of alkyne to the metal, which is followed by elimination of trimethylsilyldiazomethane and formation of [(PEt 3) 3Rh(CCR)].