Recent Advances in the Construction of Coumarin or Quinolin-2-ones Compounds via Radical Cascade Reactions

: Free radical reactions occupy an important position in synthetic organic chemistry as well as medicinal chemistry, significantly complementing and extending the synthesis of coumarin or quinolin-2-one compounds. Moreover, the use of constructing coumarin or quinolin-2-one compounds functionalized at the C3 position has certain advantages over traditional noble metalcatalyzed or high-temperature cyclization, which is more in line with the advocates of green chemistry. The design of alkenes or alkynes as radical acceptors for cascade reactions presents a novel and robust approach to obtaining coumarin or quinolin-2-one molecules. These radical cascade cyclization reactions have been well explored and studied over the past decade. As a result, we have compiled a review of the rapidly developing cutting-edge research in this field, featuring typical examples and in-depth exploration of the underlying mechanisms.