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• W2016551454 endingPage "611" @default.
• W2016551454 startingPage "591" @default.
• W2016551454 abstract "Hydrocarbyl complexes, (tBu3SiNH)3ZrR (1-R), were prepared via metatheses of (tBu3SiNH)3ZrCl (1-Cl) with RMgX or RLi (R = Me, Et, Cy, CH2Ph, allyl, CHCH2, Ph, CH2tBu, C⋮CPh, C⋮CtBu), through addition of isobutylene, H2CCCMe2, and acetylene to 1-H (R = iBu, dma, or CHCH2), and by CH-bond activation; thermal 1,2-RH-elimination from 1-R produced putative (tBu3SiNH)2ZrNSitBu3 (2), which was subsequently trapped by R‘H. Thermolysis of 1-R (∼100 °C, R = Me or Cy) in the presence of H2, c-C3H6, and CH4 in cyclohexane or neat C6H6, mesitylene, and toluene afforded 1-R (R = H, cPr, Me, Ph, CH2-3,5-Me2C6H3) and a mixture of 1-CH2Ph and 1-C6H4Me, respectively. Exposure of 1-Cy to C2H4 or C6H6 in cyclohexane provided 1-CHCH2 or 1-Ph, respectively, but further reaction produced 12-(trans-HCCH) and 12-(p-C6H4) through double CH-bond activation. Thermolysis of (tBu3SiND)3ZrCH3 (1-(ND)3-CH3) in C6H6 or C6D6 yielded CH3D, and 1C6H5 or 1-(ND)3C6D5, through reversible benzene activation. Thermolysis of 1-Cy in neat cyclohexane, and with C2H6 or CMe4 present, gave cyclometalation product (tBu3SiNH)2ZrNHSitBu2CMe2CH2 (3) and 1-NHSitBu3. In THF, thermolysis of 1-CH3 afforded (tBu3SiNH)2(THF)ZrNSitBu3 (2-THF); at 25 °C, 1-H lost H2 in the presence of L (L = THF, Et2O, NMe3, PMe3) generating 2-L; 2-L (L = Et2O, py) was also prepared via ligand exchange with 2-THF. Single crystal X-ray diffraction studies of 2-THF revealed a pseudotetrahedral core, with a long ZrN bond distance (1.978(8) Å), normal Zr−N(H) bond lengths (2.028(8), 2.031(8) Å), similar amide (154.7(5), 158.1(5)°) and imide (156.9(5)°) bond angles, and little O(pπ) → Zr(dπ) bonding. Crystal data: monoclinic, P21/n, a = 13.312(5) Å, b = 18.268(6) Å, c = 20.551(7) Å, β = 92.30(3)°, Z = 4, T = 25 °C. 2-Et2O thermally eliminated C2H4 to give 1-OEt through γ-CH activation. Kinetic isotope effects (KIE) on 1,2-RD-elimination from 1-(ND)3-R (96.7 °C, R = CH3, zMe = 6.3(1); CH2Ph, zBz = 7.1(6); Ph, zPh = 4.6(4)) and CD3H loss from 1-CD3 (k(CH3)/k(CD3) = (z‘Me)3 = 1.32) revealed a symmetric H-transfer in a loose transition state. 1,2-RH-elimination rates follow: (96.7 °C, kR (×104 s-1) = 22.6(2), Ph; 15.5(2), cPr; 13.2(4), CHCH2; 10.4(2), Cy; 3.21(6), Et; 3.2(1), iBu; 1.3(1), dma; 1.51(6), H; 1.42(4), CH2tBu; 1.06(2), Me; 0.34(2), CH2-3,5-Me2C6H3; 0.169(3), CH2Ph). Competition for (tBu3SiNH)2ZrNSitBu3 (2) by RH/R‘H and equilibria provided information about the stabilities of 1-R relative to 1-cPr (R = cPr (0.0 kcal/mol) < Ph (0.3) < CH2Ph (0.7) < Me (1.2) < CH2tBu (≥7.6) < Et (≥7.8) < Cy (≥10.9)). Transition state energies afforded relative C−H bond activation selectivities (ΔΔG⧧ relative to cPr-H): cPrH ≈ ArH (0.0 kcal/mol) > MeH (3.4) > PhCH2H (4.0) > cyclometalation (≥8.5) > EtH (≥8.9) > tBuCH2H (≥9.3) > CyH (≥11.2). A correlation of ΔG⧧(1,2-RH-elimination) with D(R−H) indicated generally late transition states but suggested an earlier composition for the alkyls, as rationalized through a Hammond analysis. Correlation of ΔG⧧(1,2-RH-elimination) with RH proton affinity implicated tight binding of RH in the transition state and possible RH-binding intermediates (2-RH). 1,2-HC⋮CR-elimination from 1-C⋮CR was not observed, but second-order exchanges of 1-C⋮CPh with tBuC⋮CH, and 1-C⋮CtBu with HC⋮CPh were indicative of an associative pathway. All data can be accommodated by the following mechanism: 1-R + R‘H ⇌ 2-RH + R‘H ⇌ 2-R‘H + RH ⇌ 1-R‘ + RH; a variant where 2 mediates reversible 2-RH + R‘H exchange is less likely." @default.
• W2016551454 created "2016-06-24" @default.
• W2016551454 creator A5002909297 @default.
• W2016551454 creator A5040222176 @default.
• W2016551454 creator A5087650515 @default.
• W2016551454 date "1996-01-01" @default.
• W2016551454 modified "2023-10-18" @default.
• W2016551454 title "Hydrocarbon Activation via Reversible 1,2-RH-Elimination from (^tBu₃SiNH)₃ZrR: Synthetic, Structural, and Mechanistic Investigations" @default.
• W2016551454 cites W136347255 @default.
• W2016551454 cites W1508180688 @default.
• W2016551454 cites W1968416158 @default.
• W2016551454 cites W1971342692 @default.
• W2016551454 cites W1971595244 @default.
• W2016551454 cites W1973692325 @default.
• W2016551454 cites W1976320282 @default.
• W2016551454 cites W1982267487 @default.
• W2016551454 cites W1982791686 @default.
• W2016551454 cites W1985857706 @default.
• W2016551454 cites W1987901467 @default.
• W2016551454 cites W1994545977 @default.
• W2016551454 cites W1995413120 @default.
• W2016551454 cites W1996739012 @default.
• W2016551454 cites W1997887231 @default.
• W2016551454 cites W2004552738 @default.
• W2016551454 cites W2005090717 @default.
• W2016551454 cites W2005290191 @default.
• W2016551454 cites W2008851567 @default.
• W2016551454 cites W2011695546 @default.
• W2016551454 cites W2012734295 @default.
• W2016551454 cites W2013672254 @default.
• W2016551454 cites W2013726649 @default.
• W2016551454 cites W2013825004 @default.
• W2016551454 cites W2017033936 @default.
• W2016551454 cites W2017377837 @default.
• W2016551454 cites W2019132898 @default.
• W2016551454 cites W2019491151 @default.
• W2016551454 cites W2024353817 @default.
• W2016551454 cites W2027725168 @default.
• W2016551454 cites W2030958085 @default.
• W2016551454 cites W2030972158 @default.
• W2016551454 cites W2035017933 @default.
• W2016551454 cites W2035594868 @default.
• W2016551454 cites W2035638446 @default.
• W2016551454 cites W2040392025 @default.
• W2016551454 cites W2051616796 @default.
• W2016551454 cites W2052907048 @default.
• W2016551454 cites W2055542422 @default.
• W2016551454 cites W2055946100 @default.
• W2016551454 cites W2056657989 @default.
• W2016551454 cites W2060274706 @default.
• W2016551454 cites W2060295605 @default.
• W2016551454 cites W2067071816 @default.
• W2016551454 cites W2070513934 @default.
• W2016551454 cites W2070556015 @default.
• W2016551454 cites W2073614125 @default.
• W2016551454 cites W2074664376 @default.
• W2016551454 cites W2076471683 @default.
• W2016551454 cites W2078126741 @default.
• W2016551454 cites W2079084341 @default.
• W2016551454 cites W2083178838 @default.
• W2016551454 cites W2084360676 @default.
• W2016551454 cites W2085791320 @default.
• W2016551454 cites W2086559993 @default.
• W2016551454 cites W2088110266 @default.
• W2016551454 cites W2090197136 @default.
• W2016551454 cites W2091233953 @default.
• W2016551454 cites W2121175733 @default.
• W2016551454 cites W2274886058 @default.
• W2016551454 cites W2398966496 @default.
• W2016551454 cites W2404482818 @default.
• W2016551454 cites W2467293811 @default.
• W2016551454 cites W2519424229 @default.
• W2016551454 cites W255314532 @default.
• W2016551454 cites W264852378 @default.
• W2016551454 cites W286513275 @default.
• W2016551454 cites W2949331283 @default.
• W2016551454 cites W2951709330 @default.
• W2016551454 cites W2953180700 @default.
• W2016551454 cites W3136402416 @default.
• W2016551454 cites W340894558 @default.
• W2016551454 cites W67969648 @default.
• W2016551454 doi "https://doi.org/10.1021/ja950745i" @default.
• W2016551454 hasPublicationYear "1996" @default.
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