Carbon-Nitrogen Bond Cleavage by a Thorium-NHC-bpy Complex

Abstract

Actinide complexes demonstrate unparalleled reactivity towards small molecules. However, utilizing these powerful transformations in a predictable and deliberate manner remains challenging. Therefore, developing actinide systems that not only perform noteworthy chemistry but also demonstrate controllable reactivity is a key goal. We describe a bis(NHC)borate thorium-bpy complex (1) that is capable of reductively cleaving the R-NC bond in a series of organic isocyanides. In contrast to most actinide-mediated bond activations, the dealkylation event mediated by 1 is remarkably general and yields very well-defined products that assist in mechanistic elucidation. Synthesis of the rearranged but-3-enyl product from the reaction of 1 and cyclopropylmethyl isocyanide supports the notion of a radical-based mechanism.

Keywords: N-heterocyclic carbenes; bipyridine; cooperativity; isocyanide; thorium.