ISSN:
0009-2940
Keywords:
Diphosphabicyclobutanes / Valence isomerization
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
DiphosphabicyclobutanesTwo isomeric diphosphabicyclobutanes (5,11) are obtained by treatment of the phosphaalkenes X-P = C(Ph)Tms (1a) and X - P = CTms2 (1b) (X = halogen Tms = trimethylsilyl) with 2, Mg, or Na. Both syntheses proceed by coupling of two phosphaalkene units affording, however, two different diphospha-butadiene intermediates. 4 and 10 readily undergo isomerization reactions to form the diphosphabicyclobutanes. Irradiation of the phosphaalkenes Cp* - P = C(Ph)Tms (12a) and Cp* - P = CTms2 (12b) (Cp* = C5Me5) gives rise to a different reaction pathway. Dimerization of 12a, followed by homolytic cleavage of the Cp* - phosphorus bond and intramolecular recombination produces the butterfly compound 5, whereas homolytic cleavage of the Cp* - element bond in 12 b, followed by rearrangement and intermolecular recombination, affords the diphosphabicyclobutane 11.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19901230113
