Intramolecular Carbyne–Isocyanide Coupling to an Alkyne Ligand at a d4 Tungsten Center

✍ Scribed by Alexander C. Filippou; Bernhard Lungwitz; Gabriele Kociok-Köhn

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 345 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199911)1999:11<1905::aid-ejic1905>3.0.co;2-w

✦ Synopsis

Oxidative decarbonylation of Cp*(CO) 2 WϵCNEt 2 (1) with 16e carbene complex Cp*(Cl) 3 W=C(H)NEt 2 (6) after elimination of P(OMe) 3 . Complex 5 was obtained from the PhICl 2 affords the aminocarbyne complex cis-Cp* (Cl) 2 (CO)WϵCNEt 2 (2), which reacts with tBuNC to give the CO ligand-exchange reaction of 2 with P(OMe) 3 . Treatment of 6 with tBuNC yields the cationic 18e carbene complex CO substitution product cis-Cp*( Cl) 2 (tBuNC)WϵCNEt 2 (3) (Cp* = C 5 Me 5 ). Complex 3 undergoes a carbyne-isocyanide [Cp*(Cl) 2 (tBuNC) 2 W=C(H)NEt 2 ]Cl (7). The mechanism of the C-C coupling reaction of 3 to give 4 is discussed and the coupling reaction with HCl to yield the alkyne complex Cp*-(Cl) 3 W[η 2 -tBu(H)NCϵCNEt 2 ] (4). In comparison, the reaction crystal structures of 4 and 6 are described. of cis-Cp*(Cl) 2 [P(OMe) 3 ]WϵCNEt 2 (5) with HCl affords the last step a carbyneϪcarbyne coupling reaction of C affords … Ϫ N) stretching vi-[a] Fachinstitut für Anorganische und Allgemeine Chemie der Humboldt-Universität zu Berlin, bration at ν ˜ϭ 1600 and 1571 cm Ϫ1 , which indicates the Hessische Straße 1Ϫ2, D-10115 Berlin strong π conjugation of the amino group with the tung-