Aromatic reactivity : LVIII. Base-cleavage of bonds between trimethylsilyl groups and polynuclear aromatic rings

The relative rates of cleavage of aryl-SiMe₃ compounds in a mixture of 1.0 M potassium hydroxide (1 vol) and DMSO (6 vol) at 70° have been found to be as follows: (aryl = ) Ph, 1.0; 1-naphthyl, 12.5; 2-naphthyl, 4.7; 9-phenanthryl, 51; 1-pyrenyl, 71. The order of reactivity is the same as that observed for hydrogen-exchange of the corresponding hydrocarbons in cyclohexylamine containing lithium cyclohexylamide, and it seems that the stability of the aryl carbanion is the dominant influence in both cases.