Z. Naturforsch. 2014, 69b, 1269 – 1289
1,2-Hydroboration and 1,1-Carboboration of Alkynyl(ferrocenyl)vinylsilanes. Novel Siloles
Bernd Wrackmeyer1, Elena V. Klimkina1, Wolfgang Milius2, Christian Butterhof1, and Kathrin Inzenhofer1
1 Anorganische Chemie II, Universität Bayreuth, D-95440 Bayreuth, Germany
2 Anorganische Chemie I, Universität Bayreuth, D-95440 Bayreuth, Germany
Reprint requests to Prof. Dr. B. Wrackmeyer. E-mail: b.wrack@uni-bayreuth.de
Received May 7, 2014 / published online December 19, 2014
Dedicated to Professor Hubert Schmidbaur on the occasion of his 80th birthday
Alkynyl(ferrocenyl)vinylsilanes containing up to three alkynyl units were prepared and treated with 9-borabicyclo[3.3.1]nonane (9-BBN). All reactions proceeded in the beginning by regioselective 1,2-hydroboration of the vinyl group, with boron attached to the terminal carbon. This was followed by intra-molecular 1,1-carboboration, leading to fused silacarbacycles, depending on the number of C≡C bonds. Thus, new siloles and even fused siloles became available. The solution-state structures were revealed by multinuclear NMR techniques (1H, 11B, 13C, 29Si NMR), complemented by calculated single-molecule structures and calculated NMR parameters at the B3LYP/6-311+G(d,p) level of theory. In one case, the solid-state structure of a bicyclic derivative was determined.
Key words: Hydroboration, 1,1-Carboboration, Ferrocenylsilanes, Siloles, NMR Spectroscopy, DFT Calculations, X-Ray Diffraction
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