Synthesis and X-ray crystal structure of a cationic gold (I) π-(1,3-diene) complex generated via isomerization of a gold π-allene complex

• We report the isomerization of a gold tetramethylallene complex to a gold diene complex.
• Isomerization occurs slowly in the absence of base and immediately in the presence of Et3N.
• We report the X-ray structure of {[P(t-Bu)2o-biphenyl]Au[η2-H2CC(Me)−C(H)CMe2]}+ SbF6−.

The cationic gold tetramethylallene complex {[P(t-Bu)2o-biphenyl]Au(η2-Me2CCCMe2)}+ SbF6− (1) underwent formal 1,3-hydrogen migration in CD2Cl2 solution at or below room temperature in the absence of base to form the 1,3-diene complex {[P(t-Bu)2o-biphenyl]Au[η2-H2C(Me) = C(H)–C(H)CMe2]}+ SbF6− (2), which was isolated in 92% yield and analyzed by X-ray crystallography.

The cationic gold tetramethylallene complex [(P1)Au(η2-Me2CCCMe2)]+ SbF6− underwent isomerization via formal 1,3-hydrogen migration at or below room temperature in the absence of base to form the conjugated diene complex {(P1)Au[η2-H2CC(Me)−C(H)CMe2]}+ SbF6−, which was analyzed by X-ray crystallography.Figure optionsDownload as PowerPoint slide