No abstract

We report on the heterobimetallic complexes {Cu + -Co 3+ -Cu + } (3), {Cu + -Fe 3+ -Cu + } (4), {Cu 2+ -Co 3+ -Cu 2+ } (5), and {Cu 2+ -Fe 3+ -Cu 2+ } (6) and show their catalytic applications in the oxidation of hindered phenols and the oxidative coupling of terminal alkynes. The former reaction produces C-C-coupled and dealkylated products, whereas the latter leads to [a] 2113 the homo-and heterocoupling of terminal alkynes. The facile redox interconversion between Cu + and Cu 2+ for the secondary metal ions in these heterobimetallic complexes appears to be essential for the observed catalysis, and an important design aspect is better substrate accessibility and the use of molecular oxygen as the sole oxidant.portant classes of compounds. [6] Interestingly, both these reactions are oxidative in nature and the presence of a redoxactive metal facilitates the transformation. [7] Therefore it is important to design catalysts that provide redox-active metals with better substrate accessibility and transformation ability. In this context, metalloligands 1 and 2 have been shown to accommodate a variety of secondary metal ions while maintaining substrate accessibility. [3] Importantly, Lewis acidic secondary metal ions in the resultant heterobimetallic complexes and networks facilitate Beckmann rearrangement, ring-opening, and cyanation reactions, [3] whereas the presence of Cu I ions with accessible Cu 2+/+ red-Scheme 1. Metalloligands and heterobimetallic complexes discussed in this work. Crystal StructureHeterobimetallic complexes 5 and 6 are isostructural, however, one of the representative complexes, compound 5, was crystallographically characterized. [11] Complex 5 crystallizes in a triclinic cell system with the P1 space group. A thermal ellipsoidal representation of complex 5 is shown in

No abstract

No abstract

No abstract