A New One-Pot Synthesis of Dialkyl Phosphonates from Diazo Compounds and Dialkyl Hydrogen Phosphites

Transition Metal Catalyzed Insertion Reactions with Donor/Donor Carbenes

“…Alkyl phosphonates are useful as reagents in av ariety of synthetic procedures and having several methods to generate these reagents increases their accessibility and usefulness.I n 1990, Arbuzov and co-workers reported amethod to synthesize dialkyl phosphonates by PÀHinsertion from donor/donor copper carbenes and hydrogen phosphites. [77] In this novel procedure,a ryl/aryl diazo species 131 and hydrogen phosphites 130 were added to ar efluxing solution of the copper catalyst. This one-pot method afforded 5examples of dialkyl phosphonates in moderate to good yields (Table 8, entry 1).…”

Uncommon carbene insertion reactions

“…Notably, pentavalent H-phosphonates or H-phosphine oxides rather than trivalent phosphines with a lone pair were generally used as P-H donors to avoid poisoning the metal catalysts in this reaction. Arbuzov et al 46 and Polozov et al 47 verified the feasibility of P-H bond insertion of α-diazoesters, αdiazoketones and diaryldiazomethane compounds with dialkyl H-phosphonates in the presence of copper salts, enabling the facile synthesis of dialkyl phosphonates in moderate yields (Scheme 12a). Wu et al 48 and Tang et al 49 Please do not adjust margins Please do not adjust margins and benzyl carbenes generated in situ from Nsulfonylhydrazones with dialkoxyl-H-phosphonates and diarylphosphine oxides (Scheme 12b, 12c).…”

Bamford‐Stevens and Shapiro Reactions in Organic Synthesis

“…At that time, the only report of such transformation was published by Arbuzov who found that Cu(acac) 2 was an effective catalyst for PÀ H insertion on a range of diazocompounds. [13] However, Hayes performed catalyst and solvent scope studies and concluded that Cu(acac) 2 in DCM (dichloromethane) provides acceptable result. Notably, Rh 2 (OAc) 4 did not show formation of the desired product.…”

“…Following the success in preparation of α‐hydroxy, α‐amino, α‐sulfanyl and α‐sulfonyl esters, the Hayes group extended their methodology to carbene insertion in P−H bond and showed that the α‐phosphonoesters 19 could be obtained (scheme 3). At that time, the only report of such transformation was published by Arbuzov who found that Cu(acac) 2 was an effective catalyst for P−H insertion on a range of diazocompounds [13] . However, Hayes performed catalyst and solvent scope studies and concluded that Cu(acac) 2 in DCM (dichloromethane) provides acceptable result.…”