Methane Is the Best Substrate for C(sp3)鈥揌 Activation with Cp*(PMe3)Co(Me)(OTf): A Density Functional Theory Study

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• 作者：Sarina M. Bellows ; Thomas R. Cundari ; William D. Jones
• 刊名：Organometallics
• 出版年：2015
• 出版时间：August 24, 2015
• 年：2015
• 卷：34
• 期：16
• 页码：4032-4038
• 全文大小：473K
• ISSN：1520-6041

文摘

The chemical inertness of C(sp³)鈥揌 bonds has made their functionalization difficult, especially with earth-abundant 3d metals. The mechanism of C鈥揌 activation with the Co(III) complex Cp*(PMe₃)Co(CH₃)(OTf) was studied by DFT at the M06/6-31+G(d) level of theory and was determined to be in very good agreement with experimental data. The Co(III) complex can activate the C鈥揌 bond of methane through an oxidative hydrogen migration mechanism with an activation free energy of 32.4 kcal/mol in CH₂Cl₂. Although C₂H₆ and c-C₆H₁₂ have weaker C鈥揌 bonds than CH₄, their C鈥揌 activation barriers were greater at 34.9 and 45.9 kcal/mol, respectively. The C(sp³)鈥揌 and C(sp²)鈥揌 activation of this Co(III) complex is primarily driven by the sterics (鈭?i>E鈥?sub>s) of the substrates and supporting ligands and not the strength of the C鈥揌 bond.