ISSN:
1434-193X
Schlagwort(e):
Carbene complexes
;
Catalysis
;
Metallahexatrienes
;
Vinyl cyclopentadienes
;
Transmetallation
;
Rhodium
;
Tungsten
;
Chromium
;
Chemistry
;
General Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
We report on the first example of a transition metal-catalyzed cyclization reaction of a Fischer carbene complex. It comprises the generation of vinyl- and divinyl cyclopentadienes under exceedingly mild conditions at 20 °C by condensation of (1-amino-1,3-butadien-2-yl)carbene complexes (= cross-conjugated metallahexatrienes) (CO)5M=C(OEt)C(=CHNR2)CR1=CHR23 (M = Cr, W) with alkynes R3C≡CH 4 (R3 = Ph, cyclohex-1-enyl, isopropenyl, methoxymethyl, 1-trimethylsiloxycyclohex-1-yl) in the presence of catalytic amounts of [(COD)RhCl]2. The starting compounds 3 are accessible in high yields by addition of enamines (E)-R2NCH=CHR22 to (1-alkynyl)carbene complexes (CO)5M=C(OEt)C≡CR11 (M = Cr, W; R1 = Ph, cyclohex-1-enyl).
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
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