On the Staudinger Reaction of SP(N3)3 with PPh3 and(Me3Si)2N–(Me3Si)N–PPh2

✍ Scribed by Nadine Götz; Sebastian Herler; Peter Mayer; Axel Schulz; Alexander Villinger; Jan J. Weigand

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 187 KB
• Volume: 2006
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200501131

✦ Synopsis

Abstract

The Staudinger reactions of SP(N~3~)~3~ (1) with 1, 2 and 3 equiv. of triphenylphosphane PPh~3~ and (TMS)~2~N–(TMS)N–PPh~2~ (2) have been investigated (TMS = Me~3~Si). Reaction with PPh~3~ yields the single and double Staudinger products SP(N~3~)~2~NPPh~3~ (3) and SP(N~3~)(NPPh~3~)~2~ (4), but not the triple, while the reaction with 2 results only in the formation of the single Staudinger product SP(N~3~)~2~NPPh~2~[N(TMS)N(TMS)]~2~ (5). Compound 5 is air‐ and moisture‐sensitive but stable under argon over a long period in the solid state and in common organic solvents. Although there are covalently bound azide groups in 3, 4 and 5, these Staudinger products are neither shock‐ nor heat‐sensitive in contrast to 1. Furthermore 3, 4 and 5 are easily prepared in bulk (yield > 95 %), and unlimitedly stable when cooled and stored in the dark. Compound 5 is thermally stable up to over 150 °C while 3 and 4 are stable only up to 96 °C. However, when a solution of 5 is heated, a new surprising eight‐membered ring (6) is formed in an intermolecular TMS–N~3~ elimination reaction. The structure and bonding is discussed on the basis of experimental X‐ray data and theoretical B3LYP calculations (thermodynamics, energy landscape and charge distribution). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)