(methyl-d3)tris((tri-tert-butylsilyl)amino)zirconium | 118141-85-8

• 分子结构分类: 有机化合物
• 英文名称: (methyl-d3)tris((tri-tert-butylsilyl)amino)zirconium
• CAS: 118141-85-8
• 化学式: C₃₇H₈₇N₃Si₃Zr
• 分子量: 752.575
• InChiKey: TUQXIGJZFYPNRI-GSAFMDPUSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  13.74
• 重原子数：
  44.0
• 可旋转键数：
  7.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  36.09
• 氢给体数：
  3.0
• 氢受体数：
  3.0

反应信息

• 作为反应物：
  描述：

  (methyl-d3)tris((tri-tert-butylsilyl)amino)zirconium 、 全氘代环己烷 在 methane 作用下， 生成 methyltris((tri-tert-butylsilyl)amino)zirconium
  参考文献：
  名称：

  Methane and benzene activation via transient (tert-Bu3SiNH)2Zr:NSi-tert-Bu3

  摘要：

  DOI：

  10.1021/ja00234a044

文献信息

• Hydrocarbon Activation via Reversible 1,2-RH-Elimination from (^tBu₃SiNH)₃ZrR:  Synthetic, Structural, and Mechanistic Investigations
  作者：Christopher P. Schaller、Christopher C. Cummins、Peter T. Wolczanski

  DOI：10.1021/ja950745i

  日期：1996.1.1

  Hydrocarbyl complexes, ((t)Bu(3)SiNH)(3)ZrR (1-R), were prepared via metatheses of ((t)Bu(3)SiNH)(3)ZrCl (1-Cl) with RMgX or RLi (R = Me, Et, Cy, CH(2)Ph, allyl, CH=CH2, Ph, CH(2)(t)Bu, C=CPh, C=C(t)Bu), through addition of isobutylene, H2C=C=CMe(2), and acetylene to 1-H (R = (i)Bu, dma, or CH=CH2), and by CH-bond activation; thermal 1,2-RH-elimination from 1-R produced putative ((t)Bu(3)SiNH)(2)Zr=NSi(t)Bu(3) (2), which was subsequently trapped by R'H. Thermolysis of 1-R (similar to 100 degrees C, R = Me or Cy) in the presence of H-2, c-C3H6, and CH4 in cyclohexane or neat C6H6, mesitylene, and toluene afforded 1-R (R = ii, Pr-c, Me, Ph, CH2-3,5-Me(2)C(6)H(3)) and a mixture of 1-CH(2)Ph and 1-C(6)H(4)Me, respectively. Exposure of 1-Cy to C2H4 or C6H6 in cyclohexane provided 1-CH=CH2 or 1-Ph, respectively, but further reaction produced 1(2)-(trans-HC=CH) and 1(2)-(p-C6H4) through double CH-bond activation. Thermolysis of ((t)Bu(3)SiND)(3)ZrCH3 (1-(ND)(3)-CH3) in C6H6 or C6D6 yielded CH3D, and 1C(6)H(5) or 1-(ND)(3)C6D5, through reversible benzene activation. Thermolysis of l-Cy in neat cyclohexane, and with C2H6 Or CMe(4) present, gave cyclometalation product ((t)Bu(3)SiNH)(2)ZrNHSi(t)Bu(2)CMe(2)CH(2) (3) and 1-NHSi(t)Bu(3). In THF, thermolysis of 1-CH3 afforded ((t)Bu(3)SiNH)(2)-(THF)Zr=NSi(t)Bu(3) (2-THF); at 25 degrees C, 1-H lost H-2 in the presence of L (L = THF, Et(2)O, NMe(3), PMe(3)) generating 2-L; 2-L (L = Et(2)O 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 Zr=N bond distance (1.978(8) Angstrom), normal Zr-N(H) bond lengths (2.028(8), 2.031(8) Angstrom, similar amide (154.7(5), 158.1(5)degrees) and imide (156.9(5)degrees) bond angles, and little O(p pi) --> Zr(d pi) bonding. Crystal data: monoclinic, P2(1)/n, a = 13.312(5) Angstrom, b = 18.268(6) Angstrom, c = 20.551(7) Angstrom, beta = 92.30(3)degrees, Z = 4, T = 25 degrees C. 2-Et(2)O thermally eliminated C2H4 to give 1-OEt through gamma-CH activation. Kinetic isotope effects (KIE) on 1,2-RD-elimination from 1-(ND)(3)-R (95.7 degrees C, R = CH3, z(Me) = 6.3(1); CH(2)Ph, z(Bz) = 7.1(6); Ph, z(Ph) = 4.6(4)) and CD3H loss from 1-CD3((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 degrees C, k(R) (x10(4) s(-1)) = 22.6(2), Ph; 15.5(2), Pr-c; 13.2(4), CH=CH2; 10.4(2), Cy; 3.21(6), Et; 3.2(1), (i)Bu; 1.3(1), dma; 1.51(6), H; 1.42(4), CH(2)(t)Bu; 1.06(2), Me; 0.34(2), CH2-3,5-Me(2)C(6)H(3); 0.169(3), CH(2)Ph).Competition for ((t)Bu(3)SiNH)(2)Zr=NSi(t)Bu(3) (2) by RH/R'H and equilibria provided information about the stabilities of 1-R relative to 1-Pr-c (R = CPr (0.0 kcal/mol) < Ph (0.3) < CH(2)Ph (0.7) < Me (1.2) < CH(2)(t)Bu (greater than or equal to 7.6) < Et (greater than or equal to 7.8) < Cy (greater than or equal to 10.9)). Transition state energies afforded relative C-H bond activation selectivities (Delta Delta G double dagger relative to Pr-c-H): (PrH)-Pr-c approximate to ArH (0.0 kcal/mol) > MeH (3.4) > PhCH(2)H (4.0) > cyclometalation (greater than or equal to 8.5) > EtH(greater than or equal to 8.9) > (t)BuCH(2)H (greater than or equal to 9.3) > CyH (greater than or equal to 11.2). A correlation of Delta G double dagger(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 Delta G double dagger(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 (t)BuC=CH, and 1-C=C(t)Bu with HC=CPh were indicative of an associative pathway. All data can be accommodated by the following mechanism: 1-R + R'H reversible arrow 2-RH + R'H reversible arrow 2-R'H + RH reversible arrow 1-R' + RH; a variant where 2 mediates reversible 2-RH + R'H exchange is less likely.