Die Aminoalkylierung von Carbonylverbindungen mit Hilfe der Wittig-Reaktion

✍ Scribed by Adrian Marxer; Thomas Leutert

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: German
• Weight: 762 KB
• Volume: 61
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19780610519

✦ Synopsis

The Aminoalkylation of Carbonyl Compounds by the Wittig‐Reaction

The Wittig reaction would be a very suitable way to replace the carbonyl group in aldehydes and ketones by a 2‐amino‐ethylidene group if a simple and convenient method could be devised for synthesizing (2‐amino‐ethyl)triphenylphosphonium bromides 3. We have synthesized compounds of type like (2‐dialkylaminoethyl)‐, (2‐morpholino‐ethyl)‐, (2‐(1‐imidazolyl)ethyl)‐, and (2‐(1‐triazolyl)ethyl)‐triphenylphosphonium bromides (cf. Table 1), by melting at 150° the hydrobromides of triphenylphosphine and of the appropriate 2‐amino‐ethanol. The phosphonium bromides of type 3 could be converted with ketones by the Wittig reaction into the desired amino‐ethylidene compounds of type 2, e.g. 18–22 (Table 2). In the case of the reaction with 4‐chlorobenzaldehyde the steric course of the transformation was studied, and conditions were found favoring either cis or trans compounds (e.g. 27a or 27b in the reaction of the phosphonium bromide 11, cf. Table 3).