Synthesis and Structure of a (Carbene)(η2-olefin)W(CO)4 Complex

✍ Scribed by Dipl.-Chem. Klaus Angermund; Dr. Friedrich-Wilhelm Grevels; Prof. Dr. Carl Krüger; Dipl.-Chem. Volker Skibbe

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 244 KB
• Volume: 23
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.198409041

✦ Synopsis

E, they are also not hydrolyzed by conc. hydrochloric acid. 3a-c can be deprotonated with sodium hydroxide and acylated at the nitrogen.

Although in the 1,2,4-diazaphospholes a 1,3-diamino-2phosphaallyl system is still formally present, the ring closure is associated with an essential change: the color fades, the effect of R on 6(3'P) decreases, and JpCH increases considerably (to around 40 Hz, the normal value for phos-phaarene~'~]). These correspond to a change from the (presumed) cis&-position of the hydrogen in 2a to the trans,trans-position in 3a, d, g governed by the ring['']. As in pyrazoles["], the hydrogen atom on the nitrogen in 3a-c exchanges between the two N atoms so rapidly that the compounds appear symmetrical and, e.g., 3a exhibits two identical (averaged) PCH couplings (Table 1).