Generation of Stereocenters via Single-Carbon-Atom Doping Using N-Isocyanides

Among the electronically unsaturated carbon species, atomic carbon is the most challenging to use for the synthesis of organic molecules, despite its potential to forge four distinct covalent bonds at a carbon center in a single process. Single-carbon-atom doping (SCAD) into organic molecules without loss of atoms in the reactant is highly attractive because it allows for a remarkable increase in molecular complexity in a single process. We have previously reported that N-heterocyclic carbenes can serve as an atomic carbon equivalent suitable for SCAD reactions. However, that method is limited to the formation of methylene carbons, leaving the full potential of the concept unrealized. Here, we report an SCAD reaction that results in the formation of stereocenters by unlocking the reactivity of (N-isocyanoimino)triphenylphosphorane as an atomic carbon equivalent. This reagent enables the single-step conversion of a range of acyl chlorides into homologated α-chloro cyclic ketones, which proceeds via the generation of four different bonds, i.e., one C-Cl, one C-H, and two C-C bonds at the incorporated carbon atom.