Structural Analogues of Bioactive Phosphonic Acids: First Crystal Structure Characterization of Phosphonothioic and Boranophosphonic Acids

Abstract

Phosphonothioic and boranophosphonic acids have been structurally characterized for the first time by single X-ray crystallography. These two functional groups, and the corresponding phosphonic acid, were all conveniently synthesized in high yields from trityl H-phosphinic acid (Ph3CPO2H2). The resulting trityl-substituted series: Ph3CP(O)(OH)2, Ph3CP(S)(OH)2, Ph3CP(O)(BH3 −)(OH)]LH+ (L = Lewis base) is fully characterized by spectroscopic methods, and the structural characteristics are compared. The results indicate that boranophosphonic acids should be investigated anytime a bioactive phosphonic acid has been identified. The solid state arrangements of the synthesized compounds are also discussed.