Synthesis, Characterization, and Reactivity of Cationic Gold Diarylallenylidene Complexes

Methoxide abstraction from gold acetylide complexes of the form (L) Au[eta(1)-C CC(OMe) ArAr'] (L= IPr, P(tBu) 2(ortho-biphenyl); Ar/Ar'= C6H4X where X= H, Cl, Me, OMe) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) at @ 78 degrees C resulted in the formation of the corresponding cationic gold diarylallenylidene complexes [(L) Au= C= C= CArAr'](+) OTf- in >= 85 +/- 5% yield according to H-1 NMR analysis. C-13 NMR and IR spectroscopic analysis of these complexes established the arene-dependent delocalization of positive charge on both the C1 and C3 allenylidene carbon atoms. The diphenylallenylidene complex [(IPr) Au= C= C= CPh2](+) OTf- reacted with heteroatom nucleophiles at the allenylidene C1 and/or C3 carbon atom.