| 研究実績の概要 |
Metathesis of unsaturated hydrocarbons (alkenes, alkynes) as well as its numerous variations, such as cross-metathesis, ring-closing metathesis, ring-opening metathesis, ring-opening-metathesis polymerization, etc., is among the most technologically useful and ecologically friendly alkene transformations. The silicon and germanium variations of the metathesis process represent a totally new and very promising route for the synthesis of the highly reactive multiply-bonded organosilicon and organogermanium compounds, which may serve as the precursors for the advanced materials of the new generation. However, despite such evident interest, to date there were no reports about any success in the field of silicon and germanium metathesis. In this project we developed first examples of the Schrock-type alkylidene complexes of silicon and germanium, namely, silylidenes and germylidenes of the early transition metals. Unprecedented examples of the stable silylene and germylene complexes of the group 4 metals were prepared and isolated in high yields, structurally characterized and computationally studied. All experimental and computational data firmly support classification of such complexes as Schrock-type silylidenes and germylidenes. The above-described Schrock complexes readily react with a variety of unsaturated substratesforming the corresponding [2 + 2] cycloadducts, whose particular structures were comprehensively studied both experimentally and computationally. The cycloreversion of the newly synthesized metallacyclobutanes and metallacyclobutenes will be studied.
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