34187-76-3

Upstream product

• 3541-56-8 P,P-dichlorovinylphosphine 
• 122-52-1 triethyl phosphite 

Downstream Products

• 37628-08-3 4-ethoxy-3-(3-nitro-phenyl)-1-phenyl-1,4,5,6-tetrahydro-[1,2,4]diazaphosphinine 4-oxide 
• 37628-09-4 4-ethoxy-1,3-bis-(4-nitro-phenyl)-1,4,5,6-tetrahydro-[1,2,4]diazaphosphinine 4-oxide 
• 37628-05-0 4-ethoxy-1,3-diphenyl-1,4,5,6-tetrahydro-[1,2,4]diazaphosphinine 4-oxide 
• 37628-07-2 4-ethoxy-1-(4-nitro-phenyl)-3-phenyl-1,4,5,6-tetrahydro-[1,2,4]diazaphosphinine 4-oxide 
• 37628-06-1 4-ethoxy-3-(4-nitro-phenyl)-1-phenyl-1,4,5,6-tetrahydro-[1,2,4]diazaphosphinine 4-oxide 
• 682-30-4 Diethyl vinylphosphonate 
• 124480-48-4 O-ethyl-S-p-nitrophenylethenylthiophosphonate 

Relevant academic research and scientific papers

Revisiting the phospha-Wittig-Horner reaction

P,P-Dichlorophosphines 2a-c (RPCl2, R = Ph (a), t-Bu (b), 2,4,6-Me3Ph (c)) and P,P-dibromophosphines 4d,e (RPBr2, R = (i-Pr)3SiC≡C (d) and H2C=CH (e)) react with triethylphosphite under Michaelis-Arbuzov conditions to give phosphinodiphosphonates 3a-e in quantitative yields. After complexation to W(CO)5 and treatment with CH3ONa, phospha-Wittig-Horner reagents 9a,b are obtained on a multigram scale in good overall yield. Phospha-Wittig-Horner reagents with unsaturated substituents at IIIP (10d,e) can be prepared in analogous procedures; however, they prevail in an unusual ylide form that allows conjugation between the lone pair and the acetylene and vinyl π-systems, respectively. Phosphinophosphonate 9a has been characterized by X-ray crystallography and is shown to react smoothly with acetone within minutes. The resulting W(CO)5-coordinated phosphaalkene is shown to dimerize to a 1,2-diphosphitane or to undergo a 1,3-proton shift depending on the reaction conditions. In addition, a one-pot synthetic sequence starting from W(CO)5-coordinated phosphinodiphosphonates 5d,e has been developed to engage compounds with vinyl and acetylene substituents in phospha-Wittig-Horner reactions.