54039-38-2Relevant articles and documents
Vaughan, G. Alan,Sofield, Chadwick D.,Hillhouse, Gregory L.,Rheingold, Arnold L.
, p. 5491 - 5493 (1989)
Syntheses, structures, and reactivities of unusual four-membered metallacycles formed in insertion reactions of N=N=O, N=N=NR, and N=N=CR2 with (η5-C5Me5)2Zr(C 2Ph2)
Vaughan, G. Alan,Hillhouse, Gregory L.,Rheingold, Arnold L.
, p. 7994 - 8001 (2007/10/02)
Nitrous oxide reacts with Cp*2Zr(C2Ph2) (1, Cp* = η5-C5Me5) to afford an organometallic product in which N2O has been incorporated without loss of dinitrogen. This adduct, Cp*2Zr{N(O)NCPh=CPh} (2), is isolable yet thermally unstable with respect to loss of dinitrogen at ambient temperature to give the monomeric diphenyloxametallacyclobutene derivative Cp*2Zr(OCPh=CPh) (3). 3 crystallizes from toluene solution in the monoclinic space group P21/n with a = 9.194 (2) A?, b = 19.422 (4) A?, c = 16.642 (4) A?, β = 104.60 (2)°, and Z = 4. The least-squares refinement coverged to R(F) = 0.051 and R(wF) - 0.058 for the 1849 unique data with Fo > 4σ(Fo). Salient metrical parameters of the four-membered oxametallacycle include the following: Zr?C(1), 2.543 (6) A?; Zr-C(2), 2.219 (7) A?, Zr-O, 2.065 (5) A?; C(1)-C(2), 1.348 (12) A?; O-C(1), 1.440 (10) A?. 3 reacts with H2 to give the enolate hydride Cp*2Zr(H)(OCPh=CHPh) (8) and with HCl to give Cp*2ZrCl2 and deoxybenzoin. Substrates with acidic hydrogens (H2O, PhOH, O=CMe2, HC≡CH, HC≡CPh, and HC≡CtBu) react with 3 to give enolate derivatives Cp*2Zr(X)(OCPh=CHPh) (9, X = OH; 10, X = OPh; 11, X = OC(CH2)Me; 12, X = C≡CH; 13, X = C≡CPh; 14, X = C≡CtBu), respectively. In contrast, insertion reactions into the Zr-C bond of 3 are observed for (O=CH2)x, O=CHTol, O=CH(n-Hex), TolN3, Ph2CN2, CO, and tBuN≡C, affording the 5- and 6-membered metallacycles Cp*2Zr(QCPh=CPhCH2O) (15), Cp*2Zr(OCPh=CPhCHTolO) (16), Cp*2Zr{OCPh=CPhCH(n-Hex)O} (17), Cp*2Zr-{OCPh=CPhN(N=NTol)} (18), Cp*2Zr{OCPh=CPhN(N=CPh2)} (19), Cp*2Zr{OCPh=CPhC(=O)} (20), and Cp*2 Zr{OCPh=CPhC(=NtBu)} (21), respectively. p-Tolyl azide and diphenyldiazomethane react with 1 to afford Cp*2Zr{N-(N2-p-C6H4CH 3)CPh=CPh} (4) and Cp*2Zr{N(N=CPh2)CPh=CPh} (5), respectively; these complexes do not cleanly lose N2 on thermolysis. 4 crystallizes from benzene solution in the monoclinic space group P21/c with a = 9.912 (4) A?, b = 30.919 (9) A?, c = 13.583 (5) A?, β = 98.97 (2)°, and Z = 4. The least-squares refinement converged to R(F) = 0.067 and R(wF) = 0.064 for the 2439 unique data with Fo > 3σ(Fo). Important metrical parameters of the planar four-membered azametallacycle include the following: Zr-C(21), 2.285 (8) A?; Zr-N(1), 2.173 (8) A?; C(21)-C(22), 1.373 (16) A?; C(22)-N(1), 1.423 (12) A?; N(1)-N(2), 1.341 (12) A?; N(2)-N(3), 1.305 (12) A?. Water adds accross a Zr-C bond of 1 to give the hydroxy vinyl species Cp*2Zr(OH)(CPh=CHPh) (6), but H2O adds across the Zr-N bond of 5 to yield Cp*2Zr(OH){CPh=CPhNH-(N=CPh2)} (7).
