Et-+ (CH3)3CNO ->- EtN-z-Bu The use of IrCl62as an efficient scavenger for alkyl radicals is implied in Scheme I (eq 5) by the isolation of alkyl chlorides in high yields (even in the presence of a hundredfold excess of bromide ion8). In support, separate experiments do show that ethyl radicals generated unambiguously from the thermolysis of propionyl peroxide are quantitatively converted by IrCl62to ethyl chloride.9The reaction mixture consisting of reduced iridium-(III) species was reoxidized with either chlorine or lead dioxide, and the iridium(IV) was separated by silica gel chromatography. We deduce from the subsequent analysis of IrIVCl62~that one-half of the iridium(III) formed in the reaction consisted of IrniCl63-in accord with eq 3 of Scheme I. The remainder of the iridium-(III) appears as an insoluble polynuclear species and the fate of IrnICI52-formed in eq 5 has not yet been clarified.(8) Added as the quaternary ammonium salt. Compare S. N.