A procedure for Appel halogenations and dehydrations using a polystyrene supported phosphine oxide

The conversion of a commercially available polystyrene supported phosphine oxide into synthetically useful polymeric halophosphonium salts using oxalyl chloride/bromide takes place at room temperature in 5 min and generates only CO and CO2 as by-products. The polymeric halophosphonium salts so obtained are useful reagents for Appel halogenations and other dehydrative coupling reactions. This gives rise to a simple three-step synthesis cycle for Appel and related reactions using a commercially available polymeric phosphine oxide with very simple purification and no phosphorus waste.