Disulfide Promoted C−P Bond Cleavage of Phosphoramide: “P” Surrogates to Synthesize Phosphonates and Phosphinates

Abstract

A metal-free CÀ P bond cleavage reaction is described herein. Phosphoramides, a phosphine source, can react with alcohols to produce phosphonate and phosphinate derivatives in the presence of a disulfide. PÀ H 2 , P-alkyl, and P,P-dialkyl phosphoramides can be used as substrates to obtain the corresponding pentavalent phosphine products.

Synthesis of P‐Arylphosphinecarboxamide Derivatives by Addition of N‐Arylphosphinecarboxamides with Aryne Precursors

“…when the reaction was carried out at 80 °C, unfortunately, only a trace amount of product 3 a was detected (entry 6). Combined with previous researches, [8,10] the low bond energy of the C−P bond leads to the cleavage of the C−P bond under high temperature explain this phenomenon. On the contrary, decrease the temperature to 40 °C, 29% yield of 3 a was obtained by column chromatography (entry 7).…”

“…Based on the above experimental results and previous reports, [6,9,10,31] a plausible main reaction pathway for the formation of 3 a was proposed (Scheme 2). The fluoride anion attacks 2‐trimethylsilylphenyl triflate 2 a to eliminate one molecule of the trimethylsilyl trifluoromethanesulfonate (TMSOTf) to produce the benzyne intermediate A , Then the N ‐arylphosphinecarboxamide anion B attacks the aryne, resulting in the formation of the aryl anion intermediate C .…”

“…precursor 2 e gave a mixture and we are failed to separate some pure products. [30] Based on the above experimental results and previous reports, [6,9,10,31]…”

“…[5] The applications in synthetic chemistry of compound 1 were explored by Goicoechea's group, including its nucleophilic addition [6] and coordination abilities. [7] In addition, other applications including the aspects of esterification, [8] nucleophilic substitution, [9] Michael addition and CÀ P bond cleavage [10] were also studied by our groups. These studies demonstrate the applicability of compound 1 than traditional primary phosphine.…”

Novel primary phosphinecarboxamides derived from diamines

“…19 The reactivity of such species has also been demonstrated by coordination to metal centres, 20 functionalization of P–H bonds to afford secondary phosphines, 11,21 and their use as precursors to generate phosphonates. 22…”