[(Z)-5-Phenyl-2-penten-2-yl]mercury Bromide

The general part of the experimental section [1] has been presented elsewhere. The Grignard solution prepared from magnesium turnings (0.27 g, 11 mmol) and (Z)-2-bromo-5-phenyl-2-pentene (2.25 g, 10 mmol) was decanted via double-ended needle from the excess magnesium, and added over 1 hour to a stirred solution of mercuric bromide (3.96 g, 11 mmol) in dry tetrahydrofuran (20 ml). The mixture was refluxed for a further 1 hour and stirred at room temperature overnight. The mixture was centrifuged, the supernatant was decanted, and the precipitate of magnesium bromide was washed with tetrahydrofuran, centrifuged and decanted (3x30 ml cycles). The combined supernatants were evaporated under reduced pressure to yield crude (Z)-5-phenyl-2-penten-2-ylmercury bromide as a grey unstable solid that had to be used within 24 hours of synthesis.

¹H-NMR (90 MHz, CDCl₃) 1.90 (3H, bs, J_199Hg,H 186 Hz, CH₃), 2.10-2.83 (4H, m, 2xCH₂), 6.07 (1H, bt, J 6.87 Hz, J_199Hg,H 561 Hz,=CH), 6.85-7.30 (5H, m, ArH)

Acknowledgment: The authors gratefully acknowledge financial support from the Australian Research Council and The University of Sydney.