Sugamata Koh, Asakawa Teppei, Minoura Mao
Department of Chemistry, College of Science, Rikkyo University 3-34-1 Nishi-Ikebukuro, Toshima-ku Tokyo 171-8501 Japan
Chem Sci. 2024 Apr 2;15(19):7072-7078. doi: 10.1039/d4sc00093e. eCollection 2024 May 15.
The synthesis, structure, and properties of a stable, linear 2-stannapropadiene are reported. The identical C[double bond, length as m-dash]Sn bonds in this 2-stannapropadiene are the shortest hitherto reported C-Sn bonds. This 2-stannapropadiene features a Sn NMR signal at 507 ppm for the central tin atom, indicative of an unsaturated Sn oxidation state. Due to the inert-pair effect, the tin atom displays a pronounced preference for the +2 oxidation state over the +4 oxidation state. Nevertheless, by employing silyl substituents, it is possible to disrupt the inert-pair effect, leading to the formation of an isolable 2-stannapropadiene with a linear structure centered on a Sn atom. Treatment of this 2-stannapropadiene with SnBr·dioxane resulted in the formation of a novel four-membered cyclic 1,1-dibromo-1,3-distannetane, which was subsequently reduced to afford the corresponding stable four-membered cyclic bis(stannylene).
报道了一种稳定的线性2-锡杂丙二烯的合成、结构和性质。该2-锡杂丙二烯中相同的C═Sn键是迄今报道的最短的C-Sn键。这种2-锡杂丙二烯的中心锡原子在507 ppm处有一个Sn NMR信号，表明其处于不饱和Sn氧化态。由于惰性电子对效应，锡原子对+2氧化态的偏好明显高于+4氧化态。然而，通过使用硅烷基取代基，可以破坏惰性电子对效应，从而形成一种以Sn原子为中心的具有线性结构的可分离的2-锡杂丙二烯。用SnBr·二氧六环处理这种2-锡杂丙二烯，得到了一种新型的四元环状1,1-二溴-1,3-二锡环丁烷，随后将其还原得到相应的稳定四元环状双（亚锡烯）。
