Recent advances of chromone-based reactants in the catalytic asymmetric domino annulation reaction

Abstract

Chiral polycyclic chromanones are important heterocyclic frameworks that constitute the core structures of many natural products and bioactive molecules. As starting materials, the chromone-based reactants are very efficient building blocks...

Diversity synthesis of indole derivatives via catalyst control cyclization reaction of 2-indolylmethanols and azonaphthalene

“…8 Additionally, diversity-oriented synthesis is of great importance and provides quick access to structurally diversified scaffolds from the same starting materials. 9 Herein, we produce structurally diverse indole derivatives by a substitution and cycloaddition reaction by making use of the C3-nucleophilicity of 2-indolylmethanols, which was realized through catalyst control, thus realizing diversity synthesis of indole derivatives under mild reaction conditions.…”

Asymmetric Conjugate Addition of 3‐Hydroxychromen‐4‐Ones to Electron‐Deficient Olefins Catalyzed by Recyclable C2‐Symmetric Squaramide

“…Thus, 4 H ‐chromen‐4‐ones bearing electron‐withdrawing groups at position 3 react with various nucleophilic substrates under enamine, enolate or noncovalent asymmetric catalysis conditions to give functionalized 4 H ‐chroman‐4‐one derivatives [17] . This methodology enables facile synthesis of polycyclic compounds of high molecular complexity fused with other carbo‐ or heterocycles via asymmetric domino annulation reactions [17a] . On the other hand, information on stereoselective reactions of 4 H ‐chromen‐4‐ones derivatives with electrophiles is scares and, to our knowledge, is limited by asymmetric additions of 3‐hydroxy‐4 H ‐chromen‐4‐ones bearing electron‐rich enolate fragment to isatin‐derived β , γ ‐unsaturated α ‐ketoesters [18a] and to azonaphthalenes [18b] .…”

Synthetic and Computational Study of the Enantioselective [3+2]-Cycloaddition of Chromones with MBH Carbonates

“…Therefore, a number of synthetic approaches to chromanones and their derivatives have been extensively developed, most of which focus on incorporation of alkyl and/or aryl groups into position 2 and/or 3 of chromanones . In contrast, synthesis of 2,3-ring-substituted chromanones, especially with a five-membered ring, has not been well investigated . Cyclopenta­[ b ]­chromanone, a kind of 2,3-five-membered ring-fused chromanones, has been found in many biologically active natural products (Figure ), and elegant progress toward total synthesis of these natural products has been made during the past several years .…”