Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
J Am Chem Soc. 2013 Feb 27;135(8):2987-90. doi: 10.1021/ja401072j. Epub 2013 Feb 18.
Olefin metathesis is one of the most important industrial processes for the production of alkenes. In contrast, silicon versions of metathesis are unknown given the lack of available silylene transition-metal complexes suitable for [2 + 2] cycloaddition with unsaturated substrates. Here, we report the synthesis of 18-electron titanium silylene complexes featuring different Lewis base ligands and classified on the basis of structural, computational, and reactivity studies as Schrock-type silylene complexes. Because of the presence of loosely bound Lewis base ligands, such silylene complexes readily undergo reaction with simple unsaturated hydrocarbons, such as alkynes, forming the corresponding [2 + 2] cycloaddition products.
烯烃复分解反应是生产烯烃的最重要的工业过程之一。相比之下，由于缺乏适用于与不饱和底物进行[2 + 2]环加成的可用硅烯过渡金属配合物，硅烯版本的复分解反应是未知的。在这里，我们报告了具有不同路易斯碱配体的 18 电子钛硅烯配合物的合成，并根据结构、计算和反应性研究将其分类为 Schrock 型硅烯配合物。由于存在松散结合的路易斯碱配体，这种硅烯配合物容易与简单的不饱和烃（如炔烃）反应，形成相应的[2 + 2]环加成产物。
