Lewis/Brønsted acid-mediated cyclization/amidation of 1,6-enynes with nitriles: access to 3-enamide substituted dihydrobenzofurans

Abstract

A novel Lewis- and Brønsted-acid mediated cyclization/amidation reaction of 1,6-enynes with nitriles to synthesize 3-enamide-substituted dihydrobenzofurans has been developed.

Oxygen-, Nitrogen-, and Sulfur-Containing Heterocycles: Recent Advances in De Novo Synthesis and Prospect

“…The mechanism study found that the reaction might be initiated with a radical process and a carbamate complex of Cu(II) might be the active intermediate in the reaction. Similarly, we also elucidated a metal-free method for the transformation of nitriles and 1,6-enynes into enamide-substituted dihydrobenzofurans . The synergistic effect of a Lewis acid and Brønsted acid is very crucial for the success of the reaction.…”

“…Similarly, we also elucidated a metal-free method for the transformation of nitriles and 1,6enynes into enamide-substituted dihydrobenzofurans. 37 The synergistic effect of a Lewis acid and Brønsted acid is very crucial for the success of the reaction.…”

Development of novel transition metal-catalyzed synthetic approaches for the synthesis of a dihydrobenzofuran nucleus: a review

“…3). There have been many processes reported for the synthesis of dihydrobenzofurans in the past decades that involve the use of different catalytic systems, i.e., acid or base catalyzed synthesis, [24][25][26] organocatalysis, 27 salt catalyzed synthesis 28 as well as electrochemical and photochemical synthesis. 29,30 Transition metal (TM)-catalyzed reactions involving the synthesis of dihydrobenzofuran skeletons are one of the most reliable and benecial methods.…”