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Combination of 1,2‐Hydroboration and 1,1‐Organoboration: A Convenient Route to 5‐Silaspiro[4,4]nona‐1,6‐diene Derivatives
Author(s) -
Khan Ezzat,
Wrackmeyer Bernd,
Kempe Rhett
Publication year - 2008
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200800790
Subject(s) - chemistry , hydroboration , yield (engineering) , intramolecular force , nonane , acetic acid , nuclear magnetic resonance spectroscopy , diene , ring (chemistry) , stereochemistry , silanes , medicinal chemistry , organic chemistry , catalysis , silane , materials science , natural rubber , metallurgy
Dialkyn‐1‐yl(divinyl)silanes were prepared and their reactions with 9‐borabicyclo[3.3.1]nonane (9‐BBN) were studied. 1,2‐Hydroboration takes place selectively at the vinyl group, followed by intramolecular 1,1‐organoboration to form a 1‐silacyclopent‐2‐ene ring. Repetition of this sequence affords, in essentially quantitative yield, 5‐silaspiro[4,4]nona‐1,6‐diene derivatives bearing substituents in the 1,6‐positions and 9‐borabicyclo[3.3.1]nonyl groups in the 2,7‐positions. Protodeborylation with an excess amount of acetic acid gives the respective spirosilanes bearing substituents only in the 1,6‐positions. All new compounds were characterized by NMR spectroscopy in solution ( 1 H, 11 B, 13 C, 29 Si NMR) and for two examples of the spirosilanes by X‐ray structural analysis in the solid state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)