Cobalt-catalysed alkene hydronitration enabled by anomeric nitroamide

Abstract

Tertiary nitroalkanes, as well as their reduced products, α-tertiary amines, play an essential role in drug discovery as either key synthetic precursors or final motifs in targeted molecules. Existing methods to prepare tertiary nitro compounds generally rely on polar-bond disconnections, in which strong bases or highly active electrophiles are needed. Here we report the development of an anomeric nitroamide-based reagent that enables selective metal-hydride hydrogen atom transfer-based Co-catalysed alkene hydronitration for the preparation of valuable tertiary nitro compounds. This mild, scalable reaction shows broad functional group tolerance. Its synthetic application is demonstrated via late-stage nitration of complex alkenes derived from drugs and natural products, and simplifying the synthesis of a rare naturally occurring nitro sugar. Simple access to isotopically labelled ¹⁵N-containing nitro compounds is also disclosed. The anomeric nitroamide reagent was deemed safe by energetic measurements and its reactivity rationalized based on X-ray crystallographic analysis.