Phosphadioxirane Intermediates in the Reaction of Singlet Oxygen with Phosphites and Phosphines

Article abstract of DOI:10.1021/jo00071a012

Intermediates in the singlet oxygen reaction of phosphites and phosphines have been studied by trapping and tracer experiments.Trapping study with diphenyl sulfoxide revealed that the added substrate and phosphite are competing toward the same intermediate.The relative reactivity of (BuO)3P/Ph2S/Ph2SO = 300:4:1 and the negative ρ-value of -0.63 for diphenyl sulfoxides are not consistent with 1,3-dipolar phosphine peroxides, but suggest electrophilic O-transfers by cyclic phosphadioxiranes.Intermediacy of phosphadioxiranes was supported by an 18O-tracer study on the formation of rearranged diphenylphosphinate from ¹O2 and triphenylphosphine.Theoretical calculations also supported the dioxirane intermediate by predicting no existence of 1,3-dipolar peroxide.