A new approach for pyrophosphate bond formation starting from phosphoramidite derivatives by use of 6-trifluoromethyl-1-hydroxybenzotriazole-mediated O–N phosphoryl migration

A new method for pyrophosphate bond formation in the solid phase was developed by use of phosphoramidite derivatives, which were found to be readily converted by reaction with 6-trifluoromethyl-1-hydroxybenztriazole via an O–N phosphoryl rearrangement into pentavalent phosphotriester intermediates. These intermediates proved to react smoothly with not only phosphomonoesters but also phosphodiesters to give protected pyrophosphate derivatives which, in turn, could be easily deprotected to give the desired pyrophosphate derivatives.