| Popis: |
Cobalt α-alkoxyalkyl compounds [ROCH2Co(CO)3PPh3] (R = Me, Et) and [CH3(EtO)CHCo(CO)3PPh3] have been synthesized and transformed to their acyl derivatives, [R′CH(OR)C(O)Co(CO)3PPh3] 9R′ = H, CH3), using 1 atm. of CO. The α-ethoxyethyl complex [CH3(EtO)CHCo(CO)3PPh3] was generated by treating the acetyl compound [CH3C(O)Co(CO)3PPh3] with triethyloxonium hexafluorophosphate in CH2Cl2 and then reducing with LiHBEt3. The thermal instability of the resulting [CH3(EtO) CHCo(CO)3PPh3] compound precluded its full characterization, although it transformed into its acyl derivative in 82% isolated yield. The ethoxycarbene intermediate [CH3(EtO)C=Co(CO)3PPh3]+PF6−, the two alkoxymethyl complexes and the three acyl complexes have been characterized by elemental analysis and IR and NMR (1H, 13C, 31P) spectroscopy. Attempts to convert the α-alkoxyacyl complex [ROCH2C(O)Co(CO)3PPh3] and [CH3(EtO)CHC(O)Co(CO)3PPh3] into their alkoxycarbene compounds with a variety of alkylating agents instead afforded [CO(CO)3(PPh3)2]+. |
