Direct Access to Cinnoline-4-carbaldehydes: Iridium(III)-Catalyzed C–H 4 + 2 Annulation Using 2-Chloromalonaldehyde as a C 2 Synthon

Key Points

• The aim is to establish a method for synthesizing cinnoline-4-carbaldehyde derivatives through metal-catalyzed reactions.
• Utilized iridium(III) as a catalyst for C–H annulation.
• Employed 2-chloromalonaldehyde as a C2 synthon.
• Executed a dephthaloylation step for functionalization.
• Successfully synthesized cinnoline-4-carbaldehyde derivatives with high efficiency.
• Facilitated direct installation of aldehyde groups for further functionalization.