A powerful approach to cooperative group-transfer catalysis is demonstrated using the Co=Si bond of a cobalt silylene to provide two distinct sites for substrate activation. The orthogonal selectivity of the Co and Si centers enables efficient nitrene-group transfer to carbon monoxide by avoiding poisoning that would result from substrates competing for a single reactive site.
A cobalt silylene (Co=Si) linkage enables a distinct metal/ligand cooperative activation of an organic azide, where nitrene transfer occurs to and from the Co⋅⋅⋅Si linkage without ligand dissociation from the 18-electron cobalt center. This process utilizes the orthogonal binding affinities of the silicon and cobalt sites to avoid CO poisoning that would otherwise inhibit reactivity, leading to significantly improved catalytic isocyanate generation compared with related systems. The dual-site approach demonstrates the potential of metal/main-group bonds to access new and efficient catalytic pathways.
Keywords: Cobalt; Dual-Site Catalysis; Metal-Ligand Cooperation; Nitrene Transfer; Silylene.
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