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A Base-Stabilized 2‑Silaallene Yi-Fan Yang,† Cechao Foo,† Hong-Wei Xi,‡ Yongxin Li,† Kok Hwa Lim,‡ and Cheuk-Wai So*,† †
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore ‡ Division of Chemical and Biomolecular Engineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459 Singapore S Supporting Information *
ABSTRACT: The reaction of [CH2(PPh2S)2] (1) with 2 equiv of MeLi in Et2O followed by addition of 0.5 equiv of SiCl4 afforded the base-stabilized 2-silaallene [(PPh2S)2CSiC(PPh2S)2] (2). It has been characterized by X-ray crystallography, NMR spectroscopy, and theoretical studies. The results show that compound 2 comprises a C¯−Si2+−C¯ ylidic skeleton with a negative charge at the Cmethanediide atoms and two positive charges at the Si atom. The reaction of 2 with excess PriNCNPri in refluxing toluene gave the thiophosphinoyl-stabilized silene [(PPh2S)2C−Si+(NPri)2CC(PPh2S)2] (3).
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stabilized 2-silaallene [(PPh2S)2CSiC(PPh2S)2]. Its reactivity toward PriNCNPri is also described.
n the past two decades, the concepts of thermodynamic and/or kinetic stabilization have been applied successfully in the isolation of stable multiple bonded group 14 compounds. One of the well-studied examples is a compound containing a double bond between carbon and heavier group 14 elements. For example, stable silenes (>SiCGe CSnC
