Reaction mechanism of palladium-catalyzed silastannation of allenes by density functional theory

✍ Scribed by Meiyan Wang; Lin Cheng; Bo Hong; Zhijian Wu

• Book ID: 102878206
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 857 KB
• Volume: 30
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.21176

✦ Synopsis

Abstract

The reaction mechanism of Pd(0)‐catalyzed allenes silastannation reaction is investigated by the density functional method B3LYP. The overall reaction mechanism is examined. For the allene insertion step, the PdSi bond is preferred over the PdSn bond. The electronic mechanism of the allene insertion into PdSi bond to form σ‐vinylpalladium (terminal‐insertion) and σ‐allylpalladium (internal‐insertion) insertion products is discussed in terms of the electron donation and back‐donation. It is found that the electron back‐donation is significant for both terminal‐ and internal‐insertion. During allene insertion into PdSi bond, internal‐insertion is preferred over terminal‐insertion. By using methylallene, the regio‐selectivity for the monosubstituted allene insertion into PdSi and PdSn bond is analyzed. © 2008 Wiley Periodicals, Inc. J Comput Chem 2009