Hydrophosphorylation of C=O/N Bonds Using Organophosphine Oxides or Sulfides

Abstract α‐Functionalized phosphorus compounds are an important class of biologically relevant molecules. The synthesis of these compounds often proceeds through the hydrophosphorylation of a C=E bond, with the most well‐known transformation being the Kabachnik‐Fields reaction. The nature of the phosphorus reagent is an important aspect of the hydrophosphorylation reaction. The Kabachnik‐Fields reaction uses H‐phosphonates (RO) 2 P(O)H, and similarities are often applied to 2° phosphine chalcogenides (R 2 P(Ch)H). However, the reactivities of the P−C and P−OR molecules differ quite dramatically, which changes the operative mechanism as well as subsequent downstream chemistry. We provide an in‐depth analysis of hydrophosphorylation of C=E (E=O, N) bonds with organophosphine chalcogenides. Additional discussion and a critical appraisal are provided on the similarities and differences between the H‐phosphonate and phosphine chalcogenide chemistry.