Phosphinidene Transfer Reactions of the Terminal Phosphinidene Complex Cp2Zr(PC6H2-2,4,6-t-Bu3)(PMe3)
Journal of the American Chemical Society
The terminal zirconium phosphinidene complex Cp2Zr(PR*)(PMe3) (R* = C6H2-2,4,6-t-Bu3) 2 has been synthesized in high yield, and its reactivity has been investigated. The compound Cp2ZrMe(PHR*) 1 is unstable with respect to the loss of methane; in the presence of PMe3 this reaction yielded 2. Reactions of 2 with benzophenone, benzaldehyde, or isophthalaldehyde produced phosphaalkenes PhCH=PR* 3, Ph2C=PR* 4, and 1,3-C6H2(CH=PR*)25, respectively. PhN=C=PR* 6 resulted from the reaction of 2 with phenyl isothiocyanate while the use of cyclohexanone afforded the enolate Cp2Zr(PHR*)(OC6H9) 7. Phosphinidene group transfer also took place in reactions of 2 with the appropriate organic dihalide or epoxide. In this way phosphaalkenes CH2=PR* 8 and CHCl=PR* 9, phosphirane (CH2CH2PR*) 10, phospholane 1,2-C6H4(CH2PR*)211, and substituted phosphiranes (CH2CH)(CHCH2-PR*) 12, CH2C(CCH2PR*) 13, (PhCHCH(Ph)PR*) 15, and trans-(PhCHCH2PR*) 16 were synthesized. The use of propylene oxide yielded the enolate Cp2Zr(PHR*)(OCH2CH=CH2) 17. Similar reactions of 2 with heavier group 14 dihalides and sulfides furnished Cp2Zr(PR*(SiMe2Cl))Cl 18, PR*(SiMe2Cl)219, (Me2GeCl)2PR* 20, (Me2GePR*)2 21, (t-Bu2SnPR*)222, and (Me2SnPR*)2 23. Intramolecular phosphinidene transfer occurred in reactions of 2 with benzonitrile and dicyclohexylcarbodiimide, giving Cp2Zr(PMe3)(NC(Ph)(PR*)) 25 and Cp2Zr(N(Cy))2C=PR* 26, respectively. Crystallographic data are reported for compounds 22, 25b, and 26. © 1995, American Chemical Society. All rights reserved.
Breen, Tricia L. and Stephan, Douglas W.. (1995). Phosphinidene Transfer Reactions of the Terminal Phosphinidene Complex Cp2Zr(PC6H2-2,4,6-t-Bu3)(PMe3). Journal of the American Chemical Society, 117 (48), 11914-11921.