Potassium Carbonate → Triphenylphosphine Oxide

Participants

Reaction Steps

0.50 g (1.91 mmol) of triphenylphosphine, 0.42 g (1.90 mmol) of 2-bromomethylnaphthalene, 0.36 g (1.98 mmol) of p-bromobenzaldehyde, and 0.50 g (3.62 mmol) of K2CO3 were placed in a hardened-steel vial in a glove box under helium. The vial was sealed, and the sample was ball-milled for eight hours. The formed powder was first analyzed by solid state 31P{1H} CP MAS NMR spectroscopy, then loaded on a silica gel chromatography column, and the mixture of (E)- and (Z)-1-(p-bromophenyl)-2-(naphthyl)ethylenes (VII) (E:Z ratio ca. 3.5:1 by 1H NMR in CDCl3) was isolated in 93% yield, (0.54 g ) by eluation with hexane and toluene. Triphenylphosphine oxide was further obtained from the same column in 92% yield (0.53 g) using a hexane-acetone mixture as an eluant. The separation and purification of the E-isomer was performed according to the previously described procedure (Brooks et al., J. Am. Chem. Soc. 121, 5444 (1999)) by the column chromatography on silica gel.

Provenance & Evidence