Reaction of Triflates with Potassium Diethyl Phosphite. Formation of Phosphate Esters

Article abstract of DOI:10.1021/jo00165a019

Phenyl triflate and substituted analogues react with potassium diethyl phosphite in liquid ammonia to form aryl diethyl phosphate esters.The reaction formally involves loss of trifluoromethanesulfinate ion from the triflate and concomitant oxidation of phosphorus to the phosphate stage.Preliminary data suggest that, in a series of triflates, reactivity follows the order aryl > cyclohexenyl > cyclopropyl > alkyl.Studies on aryl triflates with added labeled phenoxide rule out a mechanism involving free phenoxide ion, i.e., displacement of phenoxide by nucleophilic attack of diethyl phosphite ion on sulfur followed by phosphorylation of displaced phenoxide.Three potential mechanisms, including one involving initial attack of phosphorus at sulfur, a biphilic insertion mechanism, and one involving nucleophilic attack on oxygen, are suggested, all of which could account for these observations.