Normal Pressure Double Carbonylation of Aryl Halides Using Cobalt(II) Chloride in the Presence of either Sodium Sulfide or Sodium Borohydride

Abstract
Tetracarbonylcobaltate ion generated by a treatment of cobalt(II) chloride with either sodium sulfide or sodium borohydride under a normal pressure of carbon monoxide was capable of catalyzing carbonylation of aryl halides in the presence of calcium hydroxide and methyl iodide to give arylglyoxylic acids in good selectivity.