ISSN:
0009-2940
Keywords:
Phosphaalkenes
;
Phosphorus ylides
;
phosphino-
;
fluoro-
;
alkoxy-
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Reactive E = C(p-p)π Systems, XXXII[1]. - Phosphorus Ylides Me3P = C(X)P(F)CF3 with π-Donor Substituents X = F, OMe, OEtFluorophosphaalkenes of the type F3CP = C(X)F react with tri-methylphosphane in a 1:1 molar ratio at temperatures below - 20°C to give the novel phosphorus ylides Me3P = C(X)P(F)CF3 in good yields [X = F (4), 70%; OMe (7), 62%; OEt (8), 74%]. Compounds 4, 7 and 8 are stable up to about 10°C, but decompose at higher temperatures yielding in case of 4 Me3PF2 as main product. The 31P-NMR spectra indicate a high barrier of rotation for the F3C(F)P group around the PIII-sp2C bond. The new ylides owe their existence to the electron withdrawing effect of the F3C(F)P unit which over-compensates the destabilizing influence of the fluorine or alkoxy substituents on the sp2C atom.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250307
Permalink
