New ortho-quinone methide formation: application to three-component coupling of isocyanides, aldehydes and phenols.

Herein, we wish to report a new three-component formation of heterocyclic scaffolds based on a one-pot process from simple phenols. The key step of this procedure involves an ortho-quinone methide formation from Mannich adducts under alkylative conditions. The transient o-quinone methide has been trapped in situ with indole and diketone using lithium perchlorate as catalyst. The interest of this procedure has been furthermore demonstrated by a new three-component aminobenzofuran formation from phenols, aldehydes and isocyanides.