205107-24-0Relevant articles and documents
Preparation of trimethylsilyl alkyne complexes of bis(pentamethylcyclopentadienyl)zirconium, (η5-C5Me5) 2Zr(RC≡CSiMe3), and their regioselective reactions with nitrous oxide
List, Adam K.,Koo, Kwangmo,Rheingold, Arnold L.,Hillhouse, Gregory L.
, p. 399 - 404 (2008/10/08)
Benzene solutions of Cp*2ZrCl2 (1) (Cp=η5-C5Me5) react with the alkynes Me3SiC≡CPh, Me3SiC≡C(c-C5H9) and Me3SiC≡CCMe3 in the presence of Na/Hg amalgam to afford high yields of the respective alkyne complexes Cp*2Zr(Me3SiC≡CPh) (2), Cp*2Zr{Me3SiC≡C(c-C5H9)} (3) and Cp*2Zr(Me3SiC≡CCMe3) (4) as crystalline compounds. Complex 2 crystallizes in the triclinic space group P1 with a=9.791(6),b=10.466(6),c=15.756(12) A, α=86.09(5), β=72.09(5), γ=72.06(4)° and Z=2. The least-squares refinement converged to R(F)=0.0604 and R(wF)=0.0628 for the 3655 unique data with Fo>4σ(Fo). Salient metrical parameters of the bound alkyne include the following: C(30)-C(31)=1.340(9) A; Zr-C(30)=2.178(6) A; Zr-C(31)=2.219(5) A; C(30)-C(31)-Si=141.0(5)°; C(31)-C(30)-C(26)=135.5(5)°. Nitrous oxide reacts with 2 or 3 to afford Cp*2Zr(OCR=CSiMe3) ((5) R=Ph; (6) R=c-C5H9) and 1 equiv. of N2 via an intermediate, Cp*2Zr{N(O)NCR=CSiMe3}, which is unstable with respect to loss of dinitrogen to give the oxametallacyclobutene derivatives 5 and 6. The oxygen-atom insertion is regiospecific for the Zr-C bond that is attached to the carbyl (Ph or c-C5H9) substituent. Under similar conditions, complex 4, in which the alkyne is particularly labile, gives a myriad of products in its reaction with N2O.
