Silver-Catalyzed Cross-Coupling of Isocyanides and Active Methylene Compounds by a Radical Process

Isocyanides are versatile building blocks, and have been extensively exploited in CH functionalization reactions. However, transition‐metal‐catalyzed direct CH functionalization reactions with isocyanides suffer from over‐insertion of isocyanides. Reported herein is a radical coupling/isomerization strategy for the cross‐coupling of isocyanides with active methylene compounds through silver‐catalysis. The method solves the over‐insertion issue and affords a variety of otherwise difficult to synthesize β‐aminoenones and tricarbonylmethanes under base‐ and ligand‐free conditions. This report presents a new fundamental CC bond‐forming reaction of two basic chemicals. Silver‐tongued radicals: A novel CC bond‐forming reaction was developed through the silver‐catalyzed radical cross‐coupling of isocyanides and active methylene compounds to deliver β‐aminoenones and tricarbonylmethanes. These two transformations are 100 % atom economical and the formation of β‐aminoenones is stereoselective. A radical mechanism is proposed on the basis of experimental studies.