21485-20-1Relevant academic research and scientific papers
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.
