Synthesis and Reactivity of Titanium Hydrazido Complexes Supported by Diamido-Ether Ligands

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• 作者：Junjuda Unruangsri ; Hannah Morgan ; Andrew D. Schwarz ; A. Daniel Schofield ; Philip Mountford
• 刊名：Organometallics
• 出版年：2013
• 出版时间：May 24, 2013
• 年：2013
• 卷：32
• 期：10
• 页码：3091-3107
• 全文大小：853K
• 年卷期：v.32,no.10(May 24, 2013)
• ISSN：1520-6041

文摘

The synthesis and reactivity of titanium diphenyl hydrazido(2鈭? complexes supported by the diamido-ether ligands O(2-C₆H₄NSiMe₃)₂ (N₂^ArO) and O(CH₂CH₂NSiMe₃)₂ (N₂O) are described. Reaction of Li₂N₂^ArO or Li₂N₂O with Ti(NNPh₂)Cl₂(py)₃ afforded Ti(N₂^ArO)(NNPh₂)(py)₂ (14) or Ti(N₂O)(NNPh₂)(py)₂ (15) with 魏³-mer-bound diamido-ether ligands. Reaction with ^tBu-bipy (4,4鈥?di-tert-butyl-2,2鈥?bipyridyl) or bipy (2,2鈥?bipyridyl) gave a switch to 魏³-fac-coordination. Reaction of 15 with Ar鈥睳CO (Ar鈥?= 2,6-C₆H₃ⁱPr₂) gave Ti{O(CH₂CH₂NSiMe₃)(CH₂CH₂NC(O)N(SiMe₃)Ar鈥?}-{N(NPh₂)C(O)N(Ar鈥?}, in which the substrate has inserted into a Ti鈥揘_amide bond of N₂O as well as adding to the Ti鈺怤_伪 multiple bond. With Ar鈥睳CS the [2+2] cycloaddition product Ti(N₂O){N(NPh₂)C(NAr鈥?S}(py) was obtained, and with Ar鈥睳CSe a mixture was formed including Ti₂(N₂O)₂(渭-Se)₂. Both 14 and 15 reacted with Ar^FxCN (Ar^Fx = C₆H₃F₂ or C₆F₅) to give Ti鈺怤_伪 bond insertion products of the type Ti(L){NC(Ar^Fx)NNPh₂}(py)₂ (L = N₂^ArO or N₂O) containing hydrazonamide ligands. Reaction of 14 with XylNC (Xyl = 2,6-C₆H₃Me₂) gave only the isonitrile 蟽-adduct Ti(N₂^ArO)(NNPh₂)(py)(CNXyl), whereas 15 underwent N_伪鈥揘_尾 bond reductive cleavage with ^tBuNC or XylNC forming Ti(N₂O)(NPh₂)(NCN^tBu) or Ti{O(CH₂CH₂NSiMe₃)(CH₂CH₂NCN(SiMe₃)Xyl)}(NPh₂)(NCNXyl) (27). Both contain metalated carbodiimide ligands, but in 27 an additional reaction of XylNC with the Ti鈥揘_amide bond of N₂O has taken place. Compound 15 also reacted with a number of internal alkynes RCCR鈥?(R = R鈥?= Me or Ph; R = Me, R鈥?= aryl) to give N_伪鈥揘_尾 bond reductive cleavage products of the type Ti{O(CH₂CH₂NSiMe₃)(CH₂CH₂NC(R)C(R鈥?NSiMe₃}(NPh₂), again involving a reaction of a Ti鈥揘_amide bond.