Benzothiophene, benzofuran, indole, and indene derivatives are privileged heterocyclic motifs. These are present in a wide range of bioactive natural products and pharmaceutical drugs and are the subject of materials science research. However, the construction of benzothiophene, benzofuran, indole, and indene frameworks have been long-standing challenges to organic chemists. In this review, we classify the derivatives of four structures synthesized from 2-benzylidene-1-benzofuran-3-one and their analogues in terms of their ring size (from three- to ten-membered) and type (fused or spiro), as well as summarizing the developments of this field. Finally, we discuss the ring opening and 1,4-addition reactions.
Keywords: 2-benzylidene-1-benzofuran-3-one; 2-benzylidene-1-benzothiophen-3-one; cycloaddition reaction; heterocycle compounds •.
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