| Popis: |
The well-defined Pd(I) metalloradical [Pd(PtBu3)2]+ reacts with aryl and alkyl iodides at room temperature, yielding [Pd(PtBu3)(μ-I)]2 and phosphonium salts. Pd(II) aryl/alkyl derivates, reflecting net radical oxidative addition of the substrate to the metalloradical, are generated during the reaction and two examples have been isolated and crystallographically characterised.\ud The transition-metal-mediated activation of carbon–halogen bonds is the basis of widely exploited catalytic methods for the construction of organic molecules. Oxidative addition to low-coordinate Pd(0) complexes is a pervading theme, with work by Hartwig and co-workers in 2002 involving isolation of T-shaped aryl Pd(ii) halide products a key mechanistic reference point (Scheme 1A).1,2 Whilst the Pd(0)/Pd(ii) redox couple remains the workhorse, processes invoking single electron transfer and Pd(i) and Pd(iii) intermediates have been attracting growing attention.3 Well-defined monomeric examples of the former are rare,4 but as part of work in our group we recently reported the synthesis of [Pd(PtBu3)2][PF6] 1 by one-electron oxidation of [Pd(PtBu3)2] with [Fc][PF6].5 Using 1 as an exemplar, we herein present our preliminary findings exploring the activation of aryl and alkyl iodides by palladium metalloradicals.\ud \ud \ud \ud |
