Catalyst‐free access to substituted pyrano[4,3‐b]pyrrol‐4(1H)‐one derivatives through domino reaction in water.

Thus far, domino‐based reactions have received a great deal of attention as a step‐and atom‐economic route toward the synthesis of a plethora of heterocyclic molecules. In this work, we disclose a catalyst‐free domino procedure for rapid synthesis of 3‐substituted 6‐methyl‐1,2‐diarylpyrano[4,3‐b]pyrrol‐4(1H)‐one compound in water at 80°C, accompanied by multiple C‐H/C‐O bond cleavage and C‐C and C‐N bond formation. This approach is characterized by its mild reaction conditions, convenient separation, high tolerance of functional groups, and easily available starting materials, thereby offering a green and efficacious strategy for the design and synthesis of pyrano[4,3‐b]pyrrol‐4(1H)‐one derivatives by domino reaction. [ABSTRACT FROM AUTHOR]