T. Chuluunbaatar et al., A new reaction of arylphospholes: Site-selective phosphorylation through reaction with phosphorus tribromide, MAGY KEM FO, 107(5), 2001, pp. 218-220
The reaction of arylphospholes 1a-c with phosphorus tribromide followed by
treatment with morpholine afforded 2- or 3-substituted species 3a,b or 7 wh
ich after oxidation gave 4a,b or 8 in a selective manner.