Beiträge zur Chemie des Bors, 221. Kinetische und thermodynamische Produktkontrolle bei der Addition von HX-Verbindungen an ein Amino-phosphanylimino-boran R2NBNPR2′

✍ Scribed by Nöth, Heinrich ;Stolpmann, Holger ;Thomann, Martina

• Publisher: Wiley (John Wiley & Sons)
• Year: 1994
• Tongue: English
• Weight: 524 KB
• Volume: 127
• Category: Article
• ISSN: 0009-2940
• DOI: 10.1002/cber.19941270112

✦ Synopsis

Contributions to the Chemistry of Boron, 221^[1]^. — Kinetic and Thermodynamic Product Control in the Addition of HX Compounds to an Amino Phosphanylimino Borane R~2~NBNPR~2~′

The reaction of equimolar amounts of HI with tmp=BNP__t__Bu~2~ (3) (tmp = 2,2,6,6‐tetramethylpiperidino group) in an unpolar solvent yields the phosphonium salt [tmp‐BNPH__t__Bu~2~]I (4). No such well‐defined reaction was observed with triflic or tetrafluoroboric acid. In contrast, HCl reacts with 3 to produce a mixture of tmp‐B(Cl)‐NH‐P__t__Bu~2~ (5) and tmp—B(Cl)—NPH__t__Bu~2~ (6). On heating or on standing at ambient temperature the unique proton of 5 migrates from the N to the P atom with formation of 6, which, therefore, is thermodynamically more stable than 5.