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

The hydrophosphorylation of C=E bonds results in the formation of α-functionalized phosphine chalcogenides. There are a myriad of phosphorus reagents and unsaturated units that can undergo this reaction. A close examination into the mechanism and scope of this reaction using organophosphine chalcogenides is provided, as well as a critical comparison between organophosphine chalcogenides and known H-phosphonate chemistry.

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)₂P(O)H, and similarities are often applied to 2° phosphine chalcogenides (R₂P(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.

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