Tandem Reaction of Phenyl α‐Cyano‐α‐arylacetates with Quinone Monoimines

Abstract

A tandem reaction of phenyl α‐cyano‐α‐arylacetates with quinone monoimines was presented, which allowed for the synthesis of various 2‐aminobenzofuran derivatives in low to moderate yields. This method is applicable to a series of phenyl α‐cyano‐α‐arylacetates with various aryl groups and quinone monoimines with different substituents. In addition, a pausible mechanism was proposed.

Recent Advances in the Domino Annulation Reaction of Quinone Imines

“…In 2019, they found that tandem conjugate addition and C–O ester migration occurred in refluxing acetonitrile to give various 2,2-diarylacetonitriles in generally good yields (not shown) [ 76 ]. In 2021, they found that an organic base could also promote the [3 + 2] cycloaddition reaction of para -quinone monoimines 3 with α-cyano-α-arylacetates 112 but resulted in the formation of 2-aminobenzofuran 113 , which was protected with di- tert -butyl dicarbonate to give 114 in moderate to good yields ( Scheme 25 ) [ 77 ]. For the reaction mechanism, 1,4-diazabicyclo[2.2.2]octane (DABCO) promoted the deprotonation of phenyl α-cyano arylacetates 112 to give enolates 115 .…”