Transition-Metal-Free C–O or C–N Bond Formation Reactions from α-Ketosulfonyl Hydrazones with Alkyl Halides or Amines

Diazo compounds can easily generate reactive ketenes by the Wolff rearrangement and construct diverse functionalized skeletons. Here, we describe a metal-free C-O or C-N bond formation reaction from readily available and stable α-ketosulfonyl hydrazones with alkyl halides or amines. Furthermore, the reaction demonstrated a broad substrate scope and afforded functionalized α,α-disubstituted esters or amides in up to 97% yields, respectively. The practical utility of this synthetic strategy was further demonstrated by gram-scale syntheses and subsequent derivatization. The preliminary mechanism studies suggest that the reaction proceeds via the initial generation of reactive ketene intermediates, followed by a nucleophilic attack pathway.