116972-70-4Relevant academic research and scientific papers
Revisiting the phospha-Wittig-Horner reaction
Arkhypchuk, Anna I.,Santoni, Marie-Pierre,Ott, Sascha
, p. 1118 - 1126 (2012/04/10)
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.
The "phospha-Wittig" reaction: A new method for building phosphorus-carbon double and single bonds from carbonyl compounds
Marinetti, Angela,Bauer, Siegfried,Ricard, Louis,Mathey, Fran?ois
, p. 793 - 798 (2008/10/08)
The so-called "phospha-Wittig" reagents [(EtO)2P(O)PHR]M(CO)5 (M = Mo, W) are obtained via the reaction of primary phosphine complexes (RPH2)M(CO)5 with lithium diisopropylamide and diethyl chlorophosphate. The corresponding anions [(EtO)2P(O) - P-R]M(CO)5 react with carbonyl compounds under mild conditions to give the phosphaalkene complexes [R1R2C=PR]M(CO)5. A study of this reaction with R = Ph, R1 = i-Pr, and R2 = H has shown that the kinetic product is the (Z)-phosphaalkene complex, whereas the thermodynamic product is the E isomer. The stereochemistry of these complexes was established by X-ray crystal structure analysis. With α-diketones, only one carbonyl bond is converted into a P=C double bond, probably for steric reasons. Most of the phosphaalkene complexes thus obtained easily react with methanol or 2,3-dimethylbutadiene. The phosphane-Mo(CO)5 complexes synthesized via such a scheme are easily transformed into the corresponding P-sulfides by simple heating with sulfur in toluene. Thus, the "phospha-Wittig" reaction can also be viewed as a new tool for building organophosphorus species with P - C single bonds.
