Silyl-substituted Tetrylene Carbonyl Complexes

过渡金属羰基配合物是一种常见的有机金属试剂，广泛应用于各种化学反应中。在寻找过渡金属的环境友好和具有成本效益的替代品时，硅和锡由于其高天然丰度和低毒性而引起了极大的兴趣。最近，我们成功地合成和分离了硅烷基取代的硅羰基配合物（R2 Si：CH 3：CO）作为稳定的化合物。以与过渡金属非常类似的方式，Si-CO键合通过CO孤对电子对到亚甲硅烷基的空p轨道的σ-捐赠来实现，并且强的C = O键通过π-反馈来活化，通过Si中心上的大体积σ-捐赠甲硅烷基基团来增强。硅羰基络合物的初步反应性类似于过渡金属羰基化合物的反应性。该项目的主要目标是进一步研究硅羰基配合物的反应性，以及Ge和Sn类似物的开发和反应性研究。工作方案包括两个主要部分。WP-1描述了较重的第14族羰基类似物R2 E：CH 3：CO（E = Ge，Sn）的合成路线和初步结果。WP-2包括详细描述的反应性研究和策略的发展，由甲硅烷基取代的tetrylene羰基配合物R2 E：CH 3：CO（E = Si，Ge，Sn）介导的催化转化。低价14族元素羰基络合物的开发将为这些物种的基本化学性质提供更深入的了解，这些物种可能成为工业上使用的催化剂的生态友好和具有成本效益的替代品。

Transition metal carbonyl complexes are common organometallic reagents and widely used as powerful catalysts in various chemical transformations. In search of environmentally benign and cost-efficient alternatives for transition metals, silicon and tin comprise great interest due to their high natural abundance and low-toxicity. Recently, we have succeeded in synthesis and isolation of silyl-substituted silicon carbonyl complexes (R2Si:⇄:CO) as stable compounds. In a very similar fashion to transition metals, the Si-CO bonding is achieved via sigma-donation of CO lone pair to an empty p orbital of the silylene and the strong C≡O bond is activated by the pi-backdonation, reinforced by bulky sigma-donating silyl groups on the Si center. The preliminary reactivity of silicon carbonyl complexes resembles that of transition metal carbonyls. The main objectives of this project are further reactivity investigations of silicon carbonyl complexes and development and reactivity studies of Ge and Sn analogues. The work programme contains two main parts. WP-1 describes the synthetic routes and preliminary results toward development of the heavier Group 14 carbonyl analogues R2E:⇄:CO (E = Ge, Sn). WP-2 consists of detailed description of the reactivity studies and strategies for development of catalytic transformations mediated by the silyl-substituted tetrylene carbonyl complexes R2E:⇄:CO (E = Si, Ge, Sn). Development of low-valent group 14 element carbonyl complexes will provide greater insights into the fundamental chemical properties of these species, which may emerge as ecologically friendly and cost-effective surrogates for industrially used catalysts.