Übergangsmetall-carben-komplexe

Conjugate addition of enolate anions to vinylcarbene complexes

“…Column chromatography (hexane) afforded 1 (0.56 g, 11%) as a bright red solid: mp 35-37 °C; NMR (CS2) 1.87 (s, 3 H, CH3), 1.90 (s, 3 H, CH3), 4.72 (s, 3 H, OCH3), 7.27 (br s, 1 H, CH=C); IR (hexane) vCo 2064 (w), 1986 (w), 1961 (m), 1949 (s) cm™1; exact mass 289.9890 (caled for C"H10O6Cr 289.9881); MS (m/e, %) 290 (14) M+, 262 (7) M -ICO, 234 (4) M -2CO, 206 (9) M -3CO, 178 (19) M -4CO, 150 (69) M -5CO, 120 (20), 107 (14), 98 (19), 91 (11), 83 (31), 82 (15), 80 (15), 67 (15), 55 (26), 53 (15), 52 (100).…”

Pentamethylcyclopentadienyl diruthenium chemistry

“…U.V. irradiation of ( 5 ) in toluene over several days surprisingly gave the p-methylene complex (6)T in 20% yield. This does not appear to be the result of cleaving the vinylidene C=C bond in that photolysis of the p.-C=C('H)2 and p-13C=CH2 derivatives of ( 5 ) afforded (9) with lithium aluminium hydride.…”

4-ansa-Metallocene complexes: synthesis of 1,1,4,4-tetramethyl-1,4-disilabutylene-bridged titanocene, zirconocene, and hafnocene derivatives

“…2 Li Cl . [Cj^SiICHjIjCH^(1) M<ci (3) ,CH3'2'si^\2 3 the lithiation of 1,4-dicyclopentadienyl-1,1,4,4-tetramethyl-1,4-disilabutane, which itself was prepared in 64% yield by the reaction of 2 mol of lithium cyclopentadienide with 1 equiv 1,4-dichloro-1,1,4,4-tetramethyl-1,4-disilabutane in THF. Reaction of 2 with the metal tetrachlorides MC14 (M = Ti, Zr, Hf) in THF and appropriate workup gave the air-stable 1,1,4,4-tetramethyl-1,4-disilabutylenebridged metallocene derivatives 3a-c in yields of around 30%.…”