BIPHASIC SYNTHESIS OF ALPHA-TETRALONE USING NICKEL-COMPLEX CATALYSTS

Organic-water interfacial autoxidation of tetralin was investigated us ing surface-active ligand complexes of transition metals (Cr, Ni, Mn, and Co) as catalysts, tetralin as the substrate and organic phase, and dodecyl sodium sulfate as an emulsifier. The major products formed un der the experimental conditions of 60 degrees C and 1 atm were alpha-t etralone and alpha-tetralol, and the highest selectivity of 71% to the desired product alpha-tetralone was achieved with nickel-tetraethylen epentamine complex. The optimum ligand to catalyst ratio was establish ed to be 2:1 for the improved reaction rate and phase separation. The organic-water phase volume ratio around which the maximum reaction rat e was attained was 2:1. The reaction order with respect to oxygen shif ted from first to zero as its partial pressure increased, and the reac tion order with respect to nickel catalyst concentration varied from 1 .7 to 1, and subsequently to 0 with further increases in the metal con centration.