American Chemical Society
ja6b13275_si_002.cif (112.41 kB)

Reactions of Isocyanides with Metal Carbyne Complexes: Isolation and Characterization of Metallacyclopropenimine Intermediates

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posted on 2017-01-20, 00:00 authored by Ming Luo, Lipeng Long, Hong Zhang, Yuhui Yang, Yuhui Hua, Gang Liu, Zhenyang Lin, Haiping Xia
η2-Iminoketenyl species have often been postulated as the intermediates in nucleophile-induced carbyne–isocyanide C–C coupling processes. However, such species are elusive. Here we report direct formation of η2-imino­ketenyl complexes from reactions of metalla­pentalyne with isocyanides. Our studies show that steric effects of N-substituents of the isocyanides play an important role in the stability of the three-membered metalla­cycles of the η2-imino­ketenyl complexes. Sterically bulky isocyanides, such as tert-butyl or 1-adamantyl isocyanides, inhibit bending at the isocyanide nitrogen atoms, a requirement for formation of η2-imino­ketenyl structures. Reactions of metalla­pentalyne with excess isocyanide allow the metal-bridged metalla­indene derivativesto be isolated as a result of the isocyanide insertion into the M–Cα σ bond of metalla­pentalyne.