914804-07-2Relevant academic research and scientific papers
Ferrocenylethynyltin compounds - Characterization and reactivity towards triethylborane
Wrackmeyer, Bernd,Kenner-Hofmann, Barbara H.,Milius, Wolfgang,Thoma, Peter,Tok, Oleg L.,Herberhold, Max
, p. 101 - 108 (2006)
Ferrocenylethynyl(trimethyl)tin (1), bis(ferrocenylethynyl)dimethyltin (2), tetrakis(ferrocenylethynyl)tin (3), and chloro(ferrocenylethynyl)dimethyltin (4) have been prepared and characterized in solution by 1H, 13C, and 119Sn NMR spectroscopy. Solid-state MAS 13C and 119Sn NMR spectra were measured for 2 and 3, and the molecular structure of one of the modifications of 2 was determined by X-ray analysis. The reactivity of 1-4 towards triethylborane has been explored. 1,1-Organoboration takes place in all cases, and the reactions are stereoselective for 1 and 4 to give the alkenes 5 and 6, respectively, in which the stannyl and the boryl groups are in cis-positions at the C=C bond. In the case of 2, the final products are the 1-stannacyclopenta-2,4-diene 7a and the 1-stanna-4-boracyclohexa-2,5-diene 8a, whereas the reaction of 2 with triisopropylborane leads selectively to the six-membered ring 8b. Zwitterionic intermediates 9a,b, in which the tin atom is coordinated side-on to the C≡C bond of an alkynylborate, have been detected by NMR spectroscopy. Compound 3 reacts with triethylborane to give a mixture of three spirotin compounds 10-12 as the final products, where the tin atom connects five- and six-membered rings. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
