Hexafluorophosphate → 6-bromo-2H-chromene

Participants

Reaction Steps

A solution of 2-allyloxy-5-bromostyrene (416 mg) in toluene (20 ml) is added dropwise to a solution of the allenylidene complex (p-cymene)RuCl(PCy3)(═C═C═CPh2)+PF6− (54 mg) in toluene (5 ml) over a period of 1.5 h at 80° C. After stirring at that temperature for another 16 h, the solvent is evaporated and the crude product purified by flash chromatography affording the title compound (341 mg, 93%). 1H NMR (200 MHz, CDCl3): d=7.15 (dd, 1H), 7.04 (d, 1H), 6.62 (d, 1H), 6.31 (dt, 1H), 5.77 (dt, 1H), 4.86 (dd, 2H).

Provenance & Evidence