Palladium‐Catalyzed Multi‐Component Reactions of <i>N</i>‐Tosylhydrazones, 2‐Iodoanilines and CO₂ towards 4‐Aryl‐2‐Quinolinones

Abstract

A palladium-catalyzed three-component reaction between N-tosylhydrazones, 2-iodoanilines and atmospheric pressure CO₂ was developed whereby a tandem carbene migration insertion/lactamization strategy afforded 4-aryl-2-quinolinones in moderate to good yields. Notably, a wide range of functional groups were tolerated in this procedure. This protocol features the simultaneous formation of four novel bonds; two C-C, one C=C and one C-N (amide), representing an efficient methodology for incorporation of CO₂ into heterocycles.