Christian Sidot

Cobalt carbonyl catalyzed sRN1 carbonylation of aryl and vinyl halides by phase transfer catalysis

Abstract The phase transfer catalyzed, cobalt carbonyi catalyzed carbonylation (1 atm. P.) of aryl and vinyi bromides under photostimulation (350 nm) affords the corresponding unsaturated acids in high yield.

Activation of reducing agents. Sodium hydride containing complex reducing agents : XIV. NaCoCO4 as an SRN1 nucleophile in the carbonylation of aryl halides by CoCRACO at atmospheric pressure. New preparation of NaCoCO4 by NaH reduction of dicobalt octacarbonyl

Abstract The only detectable cobalt carbonyl species present in CoCRACO (NaH/t-AmONa/Co(OAc) 2 /CO) (t-Am = tert-amyl) is NaCoCO 4 . The simultaneous presence of NaH, t-AmONa, NaCoCO 4 and some soluble, non-carbonyl, cobalt species allows highly catalytic carbonylation of C 6 H 5 Br under very mild conditions, while NaCoCO 4 alone can carbonylate C 6 H 5 Br under irradiation (350 nm). In the presence of t-AmONa, the reaction is highly catalytic with respect to cobalt. These results strongly suggest a S RN 1 mechanism. It is suggested that catalytic carbonylations with CoCRACO take place by a S RN 1, electron-initiated, reaction. A new, very convenient method of preparation of NaCoCO 4 by quantitative reduction of Co 2 CO 8 with NaH is also described.