Synthesis and structure of novel spirosilanes. Combination of 1,2-hydroboration and 1,1-organoboration

✍ Scribed by Bernd Wrackmeyer; Ezzat Khan; Rhett Kempe

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 212 KB
• Volume: 22
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/aoc.1411

✦ Synopsis

Abstract

The reaction of tetra(alkyn‐1‐yl)silanes Si(CC‐R^1^)~4~ 1 [R^1^ = ^t^Bu (a), Ph (b), C~6~H~4~‐4‐Me (c)] with 9‐borabicyclo[3.3.1]nonane (9‐BBN) in a 1:2 ratio affords the spirosilane derivatives 5a–c as a result of twofold intermolecular 1,2‐hydroboration, followed by twofold intramolecular 1,1‐organoboration. Intermediates 3a–c, in which two alkenyl‐ and two alkyn‐1‐yl groups are linked to silicon, were identified by NMR spectroscopy. The molecular structure of the spiro compound 5c was determined by X‐ray analysis, and the solution‐state structures of products and intermediates follow conclusively from the consistent NMR spectroscopic data sets (^1^H, ^11^B, ^13^C and ^29^Si NMR). Copyright © 2008 John Wiley & Sons, Ltd.